From the second edition (1989):
butterfly, n.
(ˈbʌtəflaɪ) Forms: 1 buttorfleoe, 3 buterfliȝe, 4 boterfleȝe, -flye, botter-, bottir-, botyrflye, (-flie), 4–6 butterflye, -flie, 5 botur-, botir-, buttur-, buttyrflye, (-flie), butter-, buttyrfle(e, botirfley, 7 butterflee, 7– butterfly. [f. butter n.1 + fly n.; with OE. buttorfléoe cf. Du. botervlieg, earlier botervlieghe, mod.G. butterfliege. The reason of the name is unknown: Wedgwood points out a Du. synonym boterschijte in Kilian, which suggests that the insect was so called from the appearance of its excrement.]

I. 1. An insect belonging to any of those diurnal species of lepidoptera, or scaly-winged flies, which have knobbed antennæ, and carry their wings erect when at rest.

a1000 Ælfric Voc. in Wr.-Wülcker 121 Papilio, buttor~fleoe. a1300 Floriz & Bl. 473 Þer fliste ut a buterfliȝe Are ihc wiste on min iȝe. c1386 Chaucer Nun's Pr. Prol. 24 Swich talkyng is nat worth a boterflye. c1440 Promp. Parv. 46 Boturflye, papilio. c1440 Hylton Scala Perf. (W. de W.) iii. xxv, Lyke to children þat renneth after butter flyes. 1548 Latimer Serm. Ploughers (Arb.) 22 The butterflye gloriethe not in hyr owne dedes. 1606 Shakes. Tr. & Cr. iii. iii. 78 Men like butter-flies, Shew not their mealie wings, but to the Summer. 1626 Bacon Sylva §696 As Butterflies quicken with heat, which were benummed with cold. 1726 Gay Fables i. xxiv. 41 And what's a Butterfly? At best He's but a caterpillar, drest. 1845 Darwin Nat. Voy. ii. 33 This [Papilio feronia] is the only butterfly which I have ever seen, that uses its legs for running. 1856 Mrs. Browning Aur. Leigh 312 Butterflies that bear Upon their blue wings such red embers round.

2. fig. a. A vain, gaudily attired person (e.g. a courtier who flutters about the court); a light-headed, inconstant person; a giddy trifler.

1605 Shakes. Lear v. iii. 13 Wee'l‥tell old tales, and laugh At gilded Butterflies. 1649 Drummond of Hawthornden Fam. Ep. Wks. (1711) 142 Long since I learned not to esteem of any golden butterflies there [at court], but as of counters. 1767 Fordyce Serm. Yng. Wom. (ed. 4) I. ii. 76 Nor will you be in danger of appearing butterflies one day, and slatterns the next. 1841 Blackw. Mag. L. 63 Coroneted carriages abound: the butterflies of fashion are abroad. 1885 M. G. Watkins in Academy 5 Dec. 379/1 Sufficiently interesting to captivate that butterfly, the ‘general reader’.

b. Applied to something flimsy, like a butterfly's wings.

a1603 T. Cartwright Confut. Rhem. N.T. (1618) 407 Those Churches which used unleavened bread, used no such butterflies as you doe; but had a great Cake which was sufficient for the whole congregation to communicate in.

c. Phr. to break a butterfly on a wheel, to use unnecessary force in destroying something fragile. Also ellipt.

1735 [see break v. 7b]. 1874 Trollope Way we live Now I. ix. 70 One doesn't want to break a butterfly on the wheel. 1931 W. Holtby Poor Caroline vi. 213, I can't bear to see a woman in the dock—butterfly on the wheel. 1951 N. Annan L. Stephen 292 Why break a butterfly on the wheel of scholarship?

d. Applied to persons whose periods of work or occupation of a place are transitory or seasonal.

1890 Chambers's Jrnl. 10 May 289/2 A ‘butterfly’ man rests for a moment to wipe his streaming brow, when the warder's stern voice bids him proceed with his work. 1891 Daily News 29 Dec. 6/4 The ‘butterfly man’, who is given cabs by the proprietors in the height of the season. 1895 Westm. Gaz. 8 Mar. 3/1 Those cabbies who come upon the streets in the fine days and disappear with the autumn leaves are called ‘butterflies’. 1902 Daily Chron. 2 June 7/1 Chelsea will welcome the return of the truant ‘butterfly’ to a region always to be associated with his artistic fame. 1912 Standard 15 Apr. 6/7 It was stated‥that the word ‘butterflies’ was a ‘technical term’ for painters and decorators who worked upon bank holidays.

e. A fanciful name (usu. pl.) used of the fluttering sensations felt before any formidable venture, esp. in phr. butterflies in the stomach, tummy, etc. Also attrib.

1908 F. Converse House of Prayer iv. 43 The three o'clock train going down the valley‥gave him a sad feeling, as if he had a butterfly in his stomach. 1943 Word Study Oct. 6/1 The expression some aviators use to describe their condition before taking off. They have ‘butterfly stomach’, they say, so marked is the fluttering in the Department of the Interior. 1944 H. Croome You've gone Astray v. 52 There was no electrical response to the movement of that firmly gentle hand, no butterflies on the backbone. 1955 J. Cannan Long Shadows viii. 132 With butterflies in her stomach‥she ascended the pretentious flight of dirty marble steps. 1958 Woman 20 Sept. 69/3, I still have ‘butterflies’ even now when I hear the Tiger Moth plane throttling back, which is my signal to prepare for the jump. 1959 Sunday Times 25 Jan. 15/5 ‘I always have butterflies when I open Parliament,’ she [sc. Queen Elizabeth II] remarked.

3. Humorous designation for: ? Some sort of legal summons or paper. Obs.

1583 Stubbes Anat. Abus. (1836) 140 If the poore manne haue not where with to pay‥out goe butterflies and writtes as thick as haile.

4. a. The guide for the reins on the front of a hansom cab, named from a fancied resemblance to a butterfly with extended wings.

1883 Standard 6 Mar. 6/3 The box covered the whole roof of the cab, preventing him [the cabman] from seeing the ‘butterfly’. 1885 Specif. Rowley & Wheeler's Patent No. 14398 The butterfly, or bracket, is screwed to the top of the Hansom cab.

b. In full butterfly bow, a bow made up or tied with the loop and end on each side spread apart like the expanded wings of a butterfly. So butterfly tie.

1870 Young Ladies' Jrnl. 1 Mar. 138/2 The butterfly bow‥is of black or coloured velvet. 1887 E. Custer Tenting on Plains (1889) xv. 502 It was then the fashion for men to wear a tiny neck-bow, called a butterfly tie. 1888 Cassell's Fam. Mag. Feb. 182/1 A bonnet à la Folle, with a tricoloured butterfly bow at the top. 1914 G. K. Chesterton Wisdom Fr. Brown xi. 264 A very young gentleman with‥a black butterfly tie. 1920 Punch 4 Aug. 97/2 The wearing of a butterfly bow with a double event collar was a solecism past forgiveness.

c. Swimming. (See quot. 1957.) Also attrib.

1936 N.Y. Times 15 Aug. 8/2 The men's 200-metre breast-stroke‥seemed to prove that the butterfly stroke is not all that some‥think it is. Ibid. 15 Aug. 8/2 Higgins‥used the butterfly only at the beginning and end [of the race]. 1937 Off. Rep. XIth Olympiad 1936 168 The breast stroke swimmers used the butterfly style, which was a failure. 1938 Times 10 Aug. 6 The butterfly, it may be explained, is made by recovering both arms at once out of the water. Ibid. 15 Aug. 5 A proposal will be made that the Butterfly stroke be abolished from international competitions. 1957 Encycl. Brit. XXI. 665/2 The butterfly is a competitive style only.‥ In the butterfly the arms pull under the body all the way to the thighs, then emerge and fling forward above surface in circular motion.

5. Coal-mining. ? A set of catches which open out so as to prevent the falling of the cage. Also attrib., as butterfly apparatus, butterfly catch.

1882 in West. Morn. News 25 Nov. 5/6 The ascending cage was hurled into the headgear, smashing the butterflies and breaking the engine rope, and had it not been for the remaining butterflies the cage must have fallen to the bottom. 1887 Daily News 11 Jan. 2/7 The butterfly apparatus‥had acted, but‥the bolts‥were torn away. 1909 Daily Chron. 8 Jan. 5/3 When the winding rope was detached the safety ‘butterfly’ catches failed to act.

II. attrib. and comb.

6. attrib. Of, pertaining to, or resembling a butterfly; fig. vain, giddy, inconstant, frivolous.

1673 R. Head Canting Acad. 103 The Bawd furnisheth them with Butterfly Garments. 1728 Mrs. Pendarves in Mrs. Delany's Corr. 165 All the butterfly men were at court last night. 1837 Fraser's Mag. XV. 239 Mr. Bailey was a dandy of the butterfly order. 1847–9 Todd Cycl. Anat. & Phys. IV. 171/2 The butterfly movement of the wings being most commonly resorted to. 1855 C. Brontë Villette i. 3 He is fond of science‥a thing his butterfly wife could not endure.

7. Simple combinations, as butterfly-brained, butterfly-catching, butterfly-hunting, butterfly-like.

1878 Browning Poets Croisic 53 The bard born to bask Butterfly-like in shine which kings and queens And baby-dauphins shed. 1881 J. Payn Grape fr. Thorn I. ii. 29 His only exercise (he was an entomologist) being butterfly-catching. 1881 Grant Allen Vignettes Nat. iv. 31 The date when flower-hunting and butterfly-hunting both begin. 1961 Times 6 Dec. 17/3 The butterfly-brained society hostess.

8. Special comb.: butterfly blenny = butterfly-fish; butterfly-block, Naut., a small block consisting of two wings containing rollers for a chain to pass over; butterfly bomb (see quot.); butterfly clack, -cock = butterfly-valve; butterfly-fish, the Ocellated Blenny (Blennius ocellaris): butterfly-flower, the genus Schizanthus; butterfly kiss (see quots.); butterfly lily = mariposa lily; butterfly lobster, a marine crustacean, Ibacus incisus, found in Tasmanian waters; butterfly lupus, lupus of the nose and cheeks; butterfly-net, a net used for catching butterflies; butterfly nose, a dog's nose when spotted or mottled; butterfly nut (Mech.), a nut provided with wings so as to be turned by the thumb and finger = thumb-nut; butterfly orchis, a book-name for Habenaria chlorantha and H. bifolia; butterfly-pea: see pea1 3; butterfly plant, the name of two Orchids, Oncidium papilio and Phalænopsis amabilis; also (quot. 1882) = butterfly flower; butterfly ray, an Australian sting-ray, Gymnura tentaculata; butterfly screw (Mech.), a screw with a thumb-piece, a thumb-screw; butterfly-shaped a. Bot. = papilionaceous; butterfly-shell, the popular name of the genus Voluta of testaceous molluscs; butterfly snail, a mollusc of the sub-class Pteropoda, a sea-butterfly; butterfly tulip = mariposa lily; butterfly-valve, a kind of double clack-valve, so called from its resemblance, when open, to a butterfly's wings; butterfly-weed, a name of various American plants, esp. Asclepias tuberosa.

1897 McIntosh & Masterman Life-Hist. Brit. Marine Food-Fishes vii. 205 (heading) *Butterfly Blenny. 1959 A. Hardy Fish & Fisheries x. 213 The beautiful little butterfly blenny‥which is not uncommon to the south west. 1882 Nares Seamanship (ed. 6) 41 Rollers or *butterfly blocks are fitted to bands round the yard. 1944 Sci. News Let. 14 Oct. 247/2 Recently they developed a ‘*butterfly bomb’, with wings that open up as soon as the bomb is released, and act like a parachute to slow its descent. 1861 N. Rankine Steam Engine 123 A pair of flap valves placed hinge to hinge (usually made of one piece of leather fastened down in the middle) constitutes a ‘*butterfly-clack’. 1740 R. Brookes Art Angling ii. vi. 187 The *Butterfly-Fish is often exposed to sale at Venice among other small Fish. 1762 B. Stillingfl. Econ. Nat. in Misc. Tracts 84 The butterfly fish‥brings forth its fœtus alive. 1881 F. Darwin in Nature XXIII. 334 It seems impossible to believe that a *butterfly-flower could be developed under such circumstances. 1871 Geo. Eliot Middlem. I. i. v. 73 Celia knelt down‥and gave her little *butterfly kiss. 1932 E. Waugh Black Mischief ii. 58 ‘I've invented a new way of kissing. You do it with your eye-lashes.’ ‘I've known that for years. It's called a butterfly kiss.’ 1945 G. Endore Methinks the Lady (1947) iii. 47 Don't you know what a butterfly kiss is?‥ You flutter your eyelashes against his cheek, and then he flutters his against yours. 1902 V. K. Chesnut Plants used by Indians Calif. 323 Calochortus venustus‥the commonest species of the Mariposa or *butterfly lilies. 1880 L. A. Meredith Tasmanian Friends & Foes 248 ‘*Butterfly lobsters’‥the shell of the head and body‥expands into something like wing-forms. 1913 Dorland Med. Dict. (ed. 7) s.v. Lupus, *Butterfly lupus. 1827 M. Wilmot Jrnl. 25 July in More Lett. (1935) 278 Edmund and Wilmot amused themselves with their *butterfly nets. 1939 T. S. Eliot Fam. Reunion ii. i. 77 The day I lost my butterfly net. 1883 G. Stables Our Friend Dog vii. 59 *Butterfly nose, a nostril with white spots in it. 1869 E. J. Reed Shipbuild. xi. 233 When the door is closed, the clamp-screws or *butterfly nuts which are hinged to the frame, are turned back from the doorway. 1597 Gerarde Herball 165 (caption) Ornithophora Candida, *Butter-flie Orchis. 1629 Parkinson Parad. xxii. 192 Orchis Hermaphroditica candida, the white Butter~flie Orchis. 1898 C. M. Yonge John Keble's Parishes xiv. 155 Butterfly or honey-suckle orchis, Habenaria. 1963 Times 25 Apr. 14/6 A solitary exquisite butterfly-orchis. 1882 Garden 11 Feb. 91/2 *Butterfly plants (Schizanthus) are a charming class of annuals. 1931 J. R. Norman Hist. Fishes xvi. 325 The *Butterfly Rays (Pteroplatea). 1876 S. Kens. Mus. Catal. No. 1146 A milled headed screw works this lift, and an adjacent *butterfly screw. 1776 Withering Bot. Arrangem. 1796 I. 306 Blossoms *butterfly-shaped, unequal. 1890 Chambers's Encycl. V. 110/2 The yet more closely allied ‘*butterfly-snails’ or Pteropods. 1886 J. M. Hutchings In Heart Sierras 92 The charming Mariposa, or ‘*Butterfly Tulip’. 1896 T. W. Sanders Encycl. Gardening (ed. 2) 47 Calochortus (Butterfly Tulip). c1865 Letheby in Circ. Sc. I. 129/1 In this tube there is placed a *butterfly-valve. 1830 Lindley Nat. Syst. Bot. 213 *Butterfly weed is a popular remedy in the United States for a variety of disorders.

Hence ˈbutterflydom, -ism, nonce-wds.

1882 H. Merivale Faucit of B. II. ii. vii. 240 The world in all its aspects bore the pleasant face of butterflydom. 1866 S. G. Osborne Lett. Educ. Yng. Children 25 That great amount of butterflyism of which we see so much in after-life.