Green’s Dictionary of Slang

1. an obvious lie.

c.1698		B.E. Dict. Canting Crew n.p.: Hummer, a loud Lie, a Rapper.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1748		Dyche & Pardon New General Eng. Dict. (5th edn).
c.1750–1882		B.M. Carew Life and Adventures.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1834		‘Jack Downing’ Andrew Jackson 260: That are king of Spain’s trumpeter [...] who anounced tu you sich a hummer, about Mr Brown’s havin borrow’d a million from Squire Biddle’s bank when he didnt owe it a single dollar.
1838		Colonist (Sydney) 23 may 3/2: In slang phrase a hummer means a liar; ‘humming,’ therefore, is here used in the common acceptation of deceiving, cheating, or lying.
1859		Matsell Vocabulum.
1895		Crowe Aus. Sl. Dict. 37: Hummer, a great lie.

2. a very energetic or lively person, a powerful lively thing.

1681		Otway Soldier’s Fortune I i: She’s a hummer; such a bona roba, ah!
1701		Cibber Love Makes a Man IV i: Odd! she’s a Hummer!
1885		Nat. Police Gaz. (NY) 19 Dec. 7/1: ‘It [a variety of punch] holds thirteen different ingredients, and every one of ’em is a hummer’ .
1889		Ally Sloper’s Half-Holiday 6 July n.p.: If Tootsie is anything as lively as the ‘Gaiety Girls,’ she must be a hummer [F&H].
1890		A.C. Gunter Miss Nobody of Nowhere 203: I just wanted to see my Tillie dance once. She’s a society hummer now.
1894		Truth (Sydney) 27 May 1/7: She looked every inch a ‘hummer’.
1909		Bisbee Dly Rev. (AZ) 13 may 5/5: He was a hummer and could talk on the superiority of a Dairy Lunch meal with the glibness of a book agent.
1912		J. London Smoke Bellew (1926) 61: Oh, they are real hummers, your boss and mine, when it comes to sheddin’ the mazuma an’ never mindin’ other folks’ feelin’s.

3. a liar.

a.1790

H.T. Potter New Dict. Cant (1795).

4. something or someone exceptional of their type.

1873		J. O’Connor Wanderings of a Vagabond 362: Ned, cramp the queen with a few dollars – she’s a hummer.
1880		S.A. Mackeever Glimpses of Gotham and City Characters 35/1: I am sure that if I didn’t like the first twenty-five cent fortune told me I would go again and to another shop. By perseverance and a liberal outlay of quarters it is possible to strike a ‘hummer’.
1892		‘John Miller’ Workingman’s Paradise 29: ‘By gum!’ interjected Ned. ‘Those girls were hummers.’.
1899		St Paul Globe (MN) 117 Apr. 4/4: I tell you, pardner, the ol’ Gazette is a hummer from top to toe.
1901		J. Flynt World of Graft 68: You’ll probably find exactly what you’re looking for in that town. It’s reported to be quite a ‘hummer’.
1901		Sydney Sportsman (Surry Hills, NSW) 5 June 3/6: [of a woman] That’s a number one hummer.
1911		C.E. Mulford Bar-20 Days 183: ‘That is a hummer of a game,’ laughed Slivers. [...] ‘You bet it’s a hummer,’ cried Boston.
1925		Smith’s Wkly (Sydney) 19 Dec. 3/2: The story of old Nick is a hummer.
1924		C. Sandburg letter 16 Nov. in Mitgang (1968) 228: Ed was pleased with your photos; the one of Debs and Helga he thought a hummer.
1935		C. Drew ‘Thirsty’s Christmas Box’ in Bulletin 25 Dec. 41/4: [of winning dice] ‘Oh, you little beauties! You dandy little hummers!’.
1936		J. Held Jr San Diego Union 27 Dec. n.p.: Let the party be a hummer!
1944		Cab Calloway New Hepsters Dict. in Calloway (1976) 252: a hummer (n.): exceptionally good. Ex., ‘Man, that boy is a hummer.’.
1944		‘Jiver’s Bible’ in D. Burley Orig. Hbk of Harlem Jive.
1947		W.E. Harney North of 23° 80: I’m Blue Bob the B— from Borroloola. I’m a hummer, I’m a roarer, I’m a ringtailed snorter.

5. an erection.

2001

‘Randy Everhard’ Tattoo of a Naked Lady 174: I palmed each asscheek as she squirmed, rubbing my hummer against her clit.