Green’s Dictionary of Slang

gin.

1728		T. Walker The Quaker’s Opera I i: qu.: What hast thou got? poor.: Sir, you may have what you please, Wind or right Nantz or South-Sea, or Cock-my-Cap, or Kill-Grief, or Comfort, or White-Tape.
1867		(con. 1600s) M. Lemon Leyton Hall I 241: Magnus was seated [...] at the back of the tavern, compounding his morning draught of cock-my-cap.

see blow a cloud under cloud n.

to pretend to be deaf, or at least to ignore by ‘not hearing’ the speaker.

1898		T. Haydon Sporting Reminiscences 112: [...] to face the music and ‘cock a deaf ’un’ to the running fire of critics, whose remarks were not of too choice or flattering a character.
1900		Sydney Sportsman (Surry Hills, NSW) 24 Oct. 1/2: Mick Dawson cocked a deaf ’un to all requests for the office.
1910		N.Z. Truth 16 Mar. 7/5: He Cocked a Deaf ’Un [...] the poor policeman murmered that he did not take much notice of what they said.
1935		Thieves Slang ms list from District Police Training Centre, Ryton-on-Dunsmore, Warwicks n.p.: Cock (or sling) a deaf ’un: To take no notice.
1952		G. Meek ‘The Ringer’ Station Days in Maoriland 104: We tried to cock a deaf ’un when the pens were counted out.
1959		F. Norman Fings I Prologue: He cocks a deaf ’un to her and walks in the direction of the street door.
1963		L.F. Freed Crime in S. Afr. 75: ‘You’re cocking me a deafie’ meant you’re trying to bluff me.
1969		F. Norman Norman’s London 22: To begin with he cocked a deaf ’un to me.
1971		T. Lewis Plender [ebook] ‘You couldn’t really expect the boys in blue to cock a deaf ’un, could you?’.
1985		J. Sullivan ‘As One Door Closes’ Only Fools and Horses [TV script] Even the listening bank cocked a deaf ’un!
2007		N. ‘Razor’ Smith Raiders 50: The screws decided to cock a deaf ’un and pretend they could see or hear nothing untoward.

an old-fashioned hat, favoured by early 19C dandies.

1841		Northern Standard 11 Dec. 4/1: An old gentleman in black, with a little white wig and a cock and pinch hat upon his head.
1856		Carlisle Jrnl 4 July 6/1: Enacting the captain in a red coat, spy-glass, and a beaver cock and pinch.
1864, 1867, 1870		Hotten Sl. Dict. 104: cock-and-pinch the old-fashioned beaver hat, affected by ‘swells’ and ‘sporting gents’ forty years ago ? cocked back and front, and pinched up at the sides.
1914		Dundee Courier 3 Mar. 8/1: The Hat in Slang [...] A by no means exhaustive list would include ‘tile,’ ‘golgotha,’ ‘canister,’ ‘castor,’ ‘chimney,’ ‘colleger,’ ‘cock and pinch,’ ‘cowshooters,’ ‘david,’ ‘digger’s delight,’ ‘fantail,’ ‘gomer,’ ‘goss,’ ‘moab,’ ‘molocher,’ ‘muffin cap,’ ‘mushroom,’ ‘pill box,’ ‘stove pipe,’ ‘thatch,’ ‘truck,’ and ‘wee jee’.
1935		A.J. Pollock Und. Speaks 23/1: Cock and pincher, a justice of the peace (cocked and pinched hat).

see under snoot n.

to dominate, to lord it over.

1855		New Monthly Mag. 105 287: We have had a try at ousting them, and can't, and the French will cock it over us for the future.
1866		J. Greenwood Little Ragamuffin 114: Get out with you! comin’ and cockin’ over us with your talk about beds.
1923		J. Manchon Le Slang.

(US) to blunder, esp. through a display of emotion.

1974

G.V. Higgins Cogan’s Trade (1975) 12: A couple guys that I was afraid’d maybe cock off and wreck it.

(W.I.) to sit around looking important, esp. with one’s feet up.

1996

Allsopp Dict. Carib. Eng. Usage.

1. to wink.

1751		Smollett Peregrine Pickle (1964) 8: Being without the sphere of his vision, he securely pilfered his tobacco, drank his rumbo, made wry faces, and, to use the vulgar phrase, cocked his eye at him, to the no small entertainment of the spectators.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Cock your eye, shut one eye, thus translated into apothecaries latin, gallus tuus ego.
1793		J.B. Moreton West India Customs and Manners 109: Creole misses, when scarcely ten, / Cock their eyes and long for men.
1811		Lex. Balatronicum.
1820		‘Peter Corcoran’ ‘King Tims the First’ in Fancy 17: I, to win a shady man, / Must do as I did do; / Cock my eyes, and so trepan—.
1836		Marryat Japhet 17: Timothy put on his hat, cocked his eye at me, and left us alone.
1842		C. Mathews Career of Puffer Hopkins 10: [He] engages in a whispered conversation [...] (enforced by the thrusting of a roll at the same time into the open hand of the scraggy gentleman) ‘There’s a current ten—make me a vice, will ye?’ The scraggy man thereupon cocks his eye significantly.
1859, 1860		Hotten Dict. of Modern Sl. etc.
1864, 1867, 1870		Hotten Sl. Dict.
1873		Sl. Dict.

2. to take a look at.

1859		J. Eastwood in N&Q Ser. 2 VIII 461: The phrase cock your eye is not at all an uncommon one in Yorkshire – meaning direct your eye, give a glance [F&H].
1912		Bulletin (Sydney) 12 Dec. 27/3: Now, just cock your eye over Schedule X.

see throw a/one’s leg over under leg n.

(W.I.) to sit around while others are working.

1996

Allsopp Dict. Carib. Eng. Usage.

1. to sit around looking important while others work.

1996

Allsopp Dict. Carib. Eng. Usage 159/1: cock up your foot/feet To sit with an air of importance, to recline, esp. with the feet up, in a lordly manner.

2. of a woman, to sit with one’s legs sprawled in what is considered an indecent manner.

1995

Francis-Jackson Official Dancehall Dict. 10: Cock-up 1. of or relating to a sexual position 2. to sit in a vulgar manner.

see under toe n.