Green’s Dictionary of Slang

tonsil n.

SE in slang uses

In compounds

tonsil hockey (n.)

kissing.

[US]Eble Campus Sl. Oct. 5: tonsil hockey – passionate kissing.
[US]Da Bomb 🌐 29: Tonsil hockey: French kissing.
[US]C. Fothergill-Brown ‘WWE Confidential Report’ 30 June 🌐 And remember how you used to nibble on The Rock’s ear [Tonsil Hockey is not an Olympic sport.], on The Rock’s neck, and you would whisper to The Rock [Tonsil Hockey is also called ‘Tonsil Boxing’ or ‘Tongue Sushi.’].
[Can]Lip-LockOttowa Citizen (Ontario) 14 Feb. E4/3: Lip-Lock Litany [...] tongue-wrestle, throw the tongue, tonsil-hockey or tennis, tongue sushi.
[US]St Louis Post-Dispatch (MO) 10 Jan. A11/3: The incoming president plays tonsil hockey with Vladimir Putin.
tonsil swabbing (n.)

open-mouthed kissing, with mutual use of the tongue.

[Can]Dly Atheneum in McGill Dly 19 Dec. 4: Hugging and kissing [...] Lollygagging, necking, pitching honey, smooching, tonsil swabbing, pawing, muzzling, flinging woo and rotten logging are other names applied to the same activity.
tonsil-tickler (n.)

(US) a (large) penis.

[US]‘Mae West in “The Hip Flipper”’ [comic strip] in B. Adelman Tijuana Bibles (1997) 96: One of the most stupendous tonsil-ticklers that had ever crashed a cherry.
tonsil twister (n.)

(US) a vocalist.

[US]Newark Advocate (OH) 2 Sept. 12/6: Didja see the skin beater slipping a wax to the tonsil twister every time he had a chance.
tonsil varnish (n.) (also tonsil bath, ...lubricator, ...oil, ...paint, ...polish, ...shocker)

alcohol or tea; also attrib.

[US]C.L. Cullen More Ex-Tank Tales 36: The Leland [Hotel], where there was another brand of tonsil lubricator.
[US]Eve. World (NY) 26 Oct. 15/1: The route between the depot and Chief Harmon’s band-house is lined with a dazzling array of tonsil-varnish works.
[US]A. Baer Two & Three 30 Dec. [synd. col.] No ward of the nation could grab any tonsil oil anywhere.
[US]Cincinnati Enquirer (OH) 12 May 12/1: ‘Give us a little “tonsil varnish”,’ rasped Pinkey McGraw.
A. Baer ‘Bugs’ Baer 14 Nov. [synd. col.] He laid off the [...] the imported tonsil shocker and the domestic palate scorcher.
[US] ‘Jargon of the Und.’ in DN V 465: tonsil bath, A drink.
[US]Mencken Amer. Lang. (4th edn) 568: It is to those days before the Civil War that we owe many of the colorful American terms for strong drink, still current, e.g., [...] coffin-varnish, bust-head, stagger-soup, tonsil-paint, squirrel-whiskey and so on.
[US]R.F. Adams Cowboy Lingo 228: The Westerner’s names for whiskey were legion [...] ‘coffin-varnish,’ ‘conversation fluid,’ ‘tonsil varnish.’.
[UK]D. Bolster Roll On My Twelve 141: Tonsil varnish ... Tea.
[Aus]J. Wynnum I’m a Jack, All Right 126: Back again for another issue of tonsil varnish.
[US]Fond Du Lac (WI) Reporter 13 Oct. 8/3: Saloon keepers called the stuff they pushed across the bars to cowboys whisky. What the cowboys called it, however, was ‘bug juice,’ ‘gut warmer,’ ‘nose paint,’ ‘red eye,’ ‘rotgut,’ ‘scamper juice,’ ‘snake poison’ or ‘tonsil varnish.’.
[US]P.J. O’Rourke Give War a Chance (2003) 110: This is the big drug — tonsil polish, idiot oil, vitamin XXX. When it comes to getting sideways we are not a buzzed nation.
[US](con. 1940s–60s) Décharné Straight from the Fridge Dad 190: Tonsil paint Alcohol.

In phrases

box (someone’s) tonsils (v.)

to kiss with the tongue, to French kiss.

[US]Eble Campus Sl. Mar. 2: box tonsils – kiss passionately.
[US]D. Lypchuk ‘A dirty little story’ in eye mag. 8 July 🌐 He boxed her tonsils and she mousled him back. She was getting all beady and soppy.
have one’s tonsils awash (v.)

(Aus.) to be drunk.

[Aus]Sun. Times (Perth) 12 Apr. 4/7: We’ve waltzed around with German girls / With our tonsils well awash.
play tonsil hockey (v.) (also play tonsil tennis)

(US campus) to kiss deeply.

[US]P. Munro Sl. U. 149: play tonsil hockey to deep, deep kiss.
[UK]K. Lette Llama Parlour 35: ‘Vondah!’ Abe gushed, covering her in kisses. They were practically playing tonsil-hockey, for God’s sake.
[US]Eble Campus Sl. Apr. 6: play tonsil tennis – kiss, pet, make out.
[US]N.Y. Post 4 Apr. 8: Minnie Driver ‘playing tonsil hockey’ Saturday night at Toronto nightclub Fluid with NSYNC’s Joey Fatone, reports Canada’s National Post, which wonders what this means for Minnie’s longtime steady, Josh Brolin.
[UK]Indep. Rev. 8 Feb. 4: Within a few minutes we were playing tonsil hockey by the Space Invaders machine.
[Ire]P. Howard PS, I Scored the Bridesmaids 116: Who was that bird you were playing tonsil tennis with last Saturday night?