Green’s Dictionary of Slang

(a) (orig. US, also chase) a glass of water, soda or beer taken after a shot of spirits, usu. to dilute the impact; from late 1980s onwards generally the other way around, a whisky chaser that is taken after drinking a pint of beer to increase the impact [1940s+ use is SE].

1891		W. De Vere ‘Jim Marshall’s New Pianner’ Tramp Poems 9: He landed one beneath his belt, just like a mornin’ bracer, / And then another followed suit, wo’t Lish Row’d call ‘a chaser’.
1898		F.P. Dunne Mr Dooley in Peace and War 178: You ask f’r a little liquor with beer f’r a chaser.
1902		C.L. Cullen More Ex-Tank Tales 9: He absent-mindedly looked around the table for a chaser, after tossing off his glass of vichy and milk.
1915		G. Bronson-Howard God’s Man 281: He’s drunk up the Hudson and took the East River for a chaser.
1927		D. Hammett ‘$106,000 Blood Money’ Story Omnibus (1966) 321: She liked rye whiskey with milk for a chaser.
1938		Flash! (Wash., DC) 17 Jan. 12/1: The following day he ate fifteen more hot dogs and drank five bottles of Pepsi-Cola for a chaser.
1949		A.I. Bezzerides Thieves’ Market 193: Give me a double shot of bourbon with a water chaser.
1952		Kerouac letter 9 Dec. in Charters I (1995) 385: I’m buying 3 dozen oysters [...] frying them in butter, with imported Chianti for a chaser, & French bread.
1958		R. Chandler Playback 19: I take mine straight with a beer chaser.
1966		M. Rumaker Exit 3 and Other Stories 112: How ’bout a fifth of my blood for a chaser?
1974		V.E. Smith Jones Men 3: The bar-line [...] dispensing six different liquors with chaser.
1985		B. Humphries Traveller’s Tool 88: After enjoying large quantities of rich Japanese tucker with Sake chasers.
1996		A. Close Official and Doubtful 237: The gallons of Heavy and the whisky chasers.
2001		J. King White Trash 260: Bob knocking back a chaser, laughing his head off.
2005		L. Redhead Rubdown [ebook] I ordered a double Jameson’s with a beer chaser.
2009		N. Flexner Disassembled Man [ebook] Everclear with a chase of whiskey.
2012		A. Bergen ‘Dread Fellow Churls’ in Crime Factory: Hard Labour [ebook] I got loaded up on a triple_shot and at least half a dozen chasers.
2024		J. Meades Empty Wigs (t/s) 543: The Poet Bultitude [...] was belching at the bar with a guest ale, a chaser or two, pork scratchings, fucking artisan pork scratchings no less.

(b) similarly used of foods.

1906		Sun (NY) 9 Sept. 3/3: It’s floating island with cocoanut cake for a chaser.
1908		‘O. Henry’ ‘Hostages to Momus’ in Gentle Grafter (1915) 202: I’d want ham and eggs, or rabbit stew, anyhow, for a chaser.
1927		C.M. Russell Trails Plowed Under 129: A tin plate loaded with stew and bannocks, with hot tea for a chaser.
1939		J. Campbell Babe is Wise 352: He [...] swallowed a couple of raw eggs with a ‘chaser’ of bread.

(c) a final touch, e.g. in clothes.

1901

‘Hugh McHugh’ Down the Line 81: For a chaser she wore one of those feather boas.

(d) in fig. use.

1907		‘Hugh McHugh’ Beat It 75: The automobile is the rich man’s wine and the poor man’s chaser.
1907		‘O. Henry’ Trimmed Lamp (1916) 169: Eagerly gulping down the strong black headlines to be followed as a chaser by the milder details of the smaller type [DA].

(e) (drugs) a dilutant.

1981

H. Gould Fort Apache, The Bronx 313: He took a spoonful of pure heroin and dropped it in an envelope. Straight with no chaser.

(a) one who runs errands.

1901

A.H. Lewis Croker 60: One of ‘His Royal Highness’s’ chasers comes sprintin’ up to me.

(b) (mainly US, also belt-chaser) a womanizer.

1894		Yale Wit and Humor 49/2: (Chess tournament) If our accomplished chasers ain’t able to pinch that Harvard Queen without giving up one of our own ladies in exchange, we would respectfully ask what the university is coming to? [OED].
1902		Okolona Messenger (MS) 22 Oct. 3/1: College slang [...] The ‘belt chaser’ walks with a ‘bird’ to the ‘birdcage (a dormitory for women students).
1902		Christian Work & Evangelist, 73 223/2: n going from church he may become a ‘belt chaser,’ walking with a ‘coed,’ and going to his dinner he has a ‘berry’ (a good thing).
1904		R. McCardell Show Girl and Her Friends 14: Boozers and chasers do not write.
1916		J. Lait ‘If a Party Meet a Party’ in Beef, Iron and Wine (1917) 97: Do I have to let a lop-eared chicken-chaser like this run me all over town and get away with it?
1930		J.P. McEvoy Hollywood Girl 235: Teddy’s got an international reputation as a chaser.
1934		J.H. O’Hara Appointment in Samarra (1935) 26: Al never heard anything about English and other women — and if English had been a chaser Al would have heard about it.
1943		R. Chandler Lady in the Lake (1952) 13: The man is nothing but a professional chaser.
1952		E. Reid Mafia 125: Anthony Robert (‘Tony’) Gizzo [...] dresses expensively, likes to eat and drink well, loves night clubs and nightlife and is a woman chaser.
1962		R. Hauser Homosexual Society 82: He’s a stupid ignorant bully, alcoholic and woman-chaser to this day.
1966		Trimble 5000 Adult Sex Words and Phrases.
1970		‘Red’ Rudensky Gonif 166: He’s a chaser and a big man around town.
1989		M. Amis London Fields 61: Now I’m no chaser, and I failed in love, but I’ve felt these powerful feminine auras.
2012		W. Keyser ‘Carny Lingo’ in http://goodmagic.com 🌐 Chaser — From mainstream slang ‘skirt chaser’, an employee who would rather "come on" to pretty women than do his job.

(c) a promiscuous woman, the female equivalent of sense 2b.

1953		J. Thompson Criminal (1993) 50: She was pretty much of a chaser. She’d take out after anything that wore pants.
c.1957		J. Maclaren-Ross ‘A House of Cards’ in Bitten by the Tarantula (2005) 229: And then of course she’s a chaser [...] Anything in trousers.

(d) (also queer-chaser) a promiscuous homosexual.

1952		J. Jones From Here to Eternity (1998) 470: Hell, if they threw all the queens and queer-chasers in Honolulu into jail, the city’d go broke tryin to feed them.
1962		R. Hauser Homosexual Society 76: When a bisexual youngster takes up with such a ‘chaser’, it is clear that he is often reluctant.

(e) (US prison) a prison officer responsible for overseeing prisoners when out of prison, e.g. on a chain gang [the potential for escape].

1992

Bentley & Corbett Prison Sl. 96: Chaser Specific officer assigned to work crews, chain gangs and escape recovery teams.

(f) a man who sexually pursues male-to-female transgender persons having male genitalia.

2021

H. Joyce Trans 55: ‘[C]hasers’—men who desire (genitally intact) transwomen. This is a relatively common male sexual taste (as evident from the number of ‘shemales’ on Pornhub, and tourists visiting Thailand for the ‘ladyboys’.