Green’s Dictionary of Slang

hatch n.2

(US, orig. naut.) the throat or mouth.

[US](con. 1918) Anderson & Stallings What Price Glory? 125: Close your hatch.
[US] in W.C. Fields By Himself (1974) 149: I am not at liberty to disclose if Miss Dooley did or did not drop a noggin or two down the hatch.
[US]R.L. Bellem ‘Coffin for a Coward’ in Hollywood Detective Dec. 🌐 The waiter [...] came back presently with more giggle juice. Bonham tossed it down his hatch.
[US]R. Chandler Long Good-Bye 139: I reached for my glass and dropped the contents down the hatch.
[UK]I. & P. Opie Lore and Lang. of Schoolchildren (1977) 214: ‘Shut the hatch’ or ‘Shut the hatch the wind’s getting in’.
[US]T. Berger Reinhart in Love (1963) 29: No sooner did it [i.e. a dish] go down your hatch than you rushed to the john, where it came right up again.
[US]‘Hy Lit’ Hy Lit’s Unbelievable Dict. of Hip Words 49: hatch – The human mouth.
[Aus]R.G. Barrett You Wouldn’t Be Dead for Quids (1989) 58: They all took a a sip. All except Sophia. About half of hers went down the hatch in one go.
[UK]N. ‘Razor’ Smith A Few Kind Words and a Loaded Gun 159: I [...] took the liquid from his hand. I turned to put it on the table, but Wade said, ‘No, no. Straight down the hatch’.

In phrases

down the hatch! (also d.h.)

(orig. naut.) a popular toast before taking a drink.

[US]Colton & Randolph Rain I 56: Down the hatch!
[US]B. Appel Brain Guy (1937) 201: Down the hatch.
[US]P. Kendall Dict. Service Sl. n.p.: down the hatch . . . a signal for the stomach to brace itself against an incoming slug of rum.
[UK]J. Curtis Look Long Upon a Monkey 214: Blencowe raised his glass. ‘Well, here’s fun. Down the hatch. Good luck, and all that sort of thing.’.
[US](con. WWII) ‘Weldon Hill’ Onionhead (1958) 60: [of medicine] A petty officer wordlessly gave him a glass full of liquid salts [...] ‘Down the hatch, mack’.
[Ire]P. Boyle At Night All Cats Are Grey 20: ‘Down the hatch and God grant you a heavier hand with the next one,’ the drink was tossed back.
[Aus]J. Wynnum I’m a Jack, All Right 41: A yellow frothing brew was set before him, with the instruction, ‘Down the hatch!’.
[US]S. King Dead Zone (1980) 229: Fuck you ulcer, I say. Down the hatch.
[Aus]R. Beckett Dinkum Aussie Dict. 21: Down the hatch: An expression uttered before taking a beer with a mate.
[NZ]McGill Reed Dict. of N.Z. Sl. 61: DH Down the hatch, or drink up.
M. MacBride ‘Sounding’ in ThugLit Mar. [ebook] Vince raised his own glass to mine, said, ‘Down the hatch’.
under the hatches (excl.) [the image of stowing cargo out of sight in a ship’s hold]

(US) get rid of, abandon.

[US]G. Herriman Dingbat Family 24 Apr. [synd. cartoon strip] Under the hatches with that comedy, woman — S’ cheap stuff.