tuna, n. — Green’s Dictionary of Slang

tuna n.

1. (US) one who believes themselves to be far more sophisticated than is the reality.

1971

2. (US gay) a homosexual sailor who only takes the passive role in fellatio.

1972

B. Rodgers Queens’ Vernacular 23: If he sells only his penis, he is a salt-seller, shore dinner or tuna (a delicious sea product).

3. (US campus/gay) an attractive man; thus hot tuna! an excl. said on seeing a sexy man.

1972		B. Rodgers Queens’ Vernacular 110: hot tuna (exclam, kwn NYC, ’71) superlative reserved for sexy men.
1977		Eble Campus Sl. Apr. 4: tuna – good-looking male.

In compounds

tuna (fish) (n.)

1. (US campus/black) a girlfriend, a woman.

1966		Current Sl. I:3 8/1: Tuna, n. A fat girl.
1973		Eble Campus Sl. Mar. 4: tuna – girl.
1980		E. Folb Runnin’ Down Some Lines 151: Women are not only characterized as land animals but as fish – trout, fish, tuna fish.
2001		(ref. to 1991) Morgan & Neil Teaching modern Foreign Langs 285: Fall 1991 A total of 79 terms about women [...] This reflects the importance of women's looks over almost everything else about them, except sexual activity: butch, GG (gangster girl), heifer, hellpig, hiddie, hobag, scud, tuna.
2018-20		T. Thorne (ed.) ‘Drill Slang Glossary’ at Forensic Linguistic Databank 🌐 Tuna - a female.

2. (orig. US black) the vagina, both positive and negative.

1980		E. Folb Runnin’ Down Some Lines 151: Sweet tuna! I’m Charlie Tuna, I’ma gonna git me a piece that nice meat! I don’ care! Dark meat, light meat, am’ no difference to me. Pussy’s pussy! [...] Tuna, that be some stanky pussy. She on d’ rag!
1991		Eble Campus Sl. Fall 2: fishy/tuna fish – women’s smell.

3. (US black) in interrog. phr. what’s your wish, tuna fish?

1943

D. Burley N.Y. Amsterdam Star-News 3 Apr. 13: What’s your wish, tuna fish? If you want to gargle, be like the bear’s brother, try and get further.

SE in slang uses

In compounds

tun(n)y-faced (n.)

(US) used as general insult, foolish.

1901		Nineteenth Century & After 50 641: [T]he stupid or tunny-faced man, the Greek equivalent to our own ‘chub-faced fool’ of Elizabethan times.
1914		G. Herriman Dingbat Family 18 Mar. [synd. cartoon strip] — You tuny-faced sandia. — Rude hombre.
1990		Cencrastus 36-43 40: We meet McPint, the lascivious macho Scottish drinker at his awful worst , ‘a tunny-faced man full of rain, corrosive fats, nicotine [etc]’.

tuna taco (n.) [taco, a Mexican cornmeal pancake]

a woman’s genitals; esp. in the context of cunnilingus.

1993–2003		Stan B. on Urban Dict. 🌐 tuna taco Another name for the female genitalia. I think I’ll go get me some tuna taco tonight.
2003		‘The Cooter Monologues’ at www.pinkhairedgirl.com 20 Jan. 🌐 Tuna Taco, Roast Beef Curtains. Both of those terms gross me the fuck out. Because they’re nasty and disgusting!

tuna wagon (n.) [its only use would be to convey fish]

(US) an old, decrepit car.

1992

J.P. Kelly ‘Monsters’ in Isaac Asimov’s Science Fiction mag., June 🌐 Riding a tuna wagon down the mean streets was bad enough, but what really spooked him was Celeste’s driving.