Green’s Dictionary of Slang

munch v.1

1. to eat, esp. enthusiastically; thus munching n. and adj.

[UK]Dekker Shoemakers’ Holiday IV i: I lacke my breakfast, tis munching time.
[UK]Middleton & Dekker Roaring Girle II ii: gos.: Jack Dapper, where shall’s all munch? j.dap.: I am for Parker’s ordinary.
[UK]‘An Amateur’ Real Life in London I 187: The Bug-destroyer munched a candle and sluiced his greasy chops with Jacky.
[UK]Sporting Times 25 Jan. 1/1: We’re neither of us such blessed fools as to use our jaws for cackling purposes when there’s a good square meal waiting to be munched.
[US] W. Safire What’s The Good Word? 304: ‘Eating’ is ‘munching.’.
[UK]S. Berkoff West in Decadence and Other Plays (1985) 96: A sandwich in the bag to munch between the films.

2. (also munch the box) to perform oral sex.

[US]Ebonics Primer at www.dolemite.com [Internet] munchin tha box Definition: to perform oral sex on a female. Example: I got that bitch nice and wet when I was munchin her box.
[US]S. King Dreamcatcher 427: Beaver’s litany of childish curses [...] munch my meat, bite my bag, shit in your fuckin hat and wear it backward.
[US]J. Ellroy ‘Hollywood Fuck Pad’ in Destination: Morgue! (2004) 239: I munch your socks off, yum, yum.
[US](con. 1973) C. Stella Johnny Porno 188: They put the hammer to her. ‘Turn informant or get used to munching muff the next dozen years’ [...] They laid it on thick.
[US]New Yorker 11-18 July [Internet] One of his fellow-protesters tells me that Hillary has had oral sex with many female world leaders (‘She’s munched with a lot of our enemies, man’).

3. (US campus) to kiss.

[US]Eble Campus Sl. Oct. 7: munch – to kiss. ‘Bob really likes to munch Karen on a date, except in front of her parents.’.

In compounds

munching house (n.)

a cheap restaurant or café.

‘Nightmarch’ Pattaya (Thailand) Mail IX:32 10 Aug. [Internet] If you decide to sit in the air-conditioned area of the munching house, you’re liable to hear background music not heard in public since about 1938.
munch-present (n.) [he fig. ‘eats’ the money]

one who takes bribes.

[UK]Awdeley Fraternitye of Vacabondes in Viles & Furnivall (1907) n.p.: Mounch present is he that is a great gentleman, for when his mayster sendeth him with a present, he will take a tast thereof by the way [F&H].

In phrases

munching the truncheon (n.) [truncheon n.]

fellatio.

[Aus]G. Seal Lingo 126: Fellatio is munchin’ the truncheon, but may be also referred to as blue-vein salami.
munch out (v.)

1. (orig. US campus) to eat voraciously, esp. as a result of smoking cannabis.

[US]Eble Campus Sl. Fall 4: munch out – to eat, particularly late night snacks.
[US]Eble Campus Sl. Spring 4: munch, munch out – eat greedily.
[US]Eble Sl. and Sociability 31: Sometimes the word + particle construction is typical of and strengthens the synonymy of a group of related verbs: [...] munch out, pig out, pork out, snort out, [...] all mean ‘to eat, usually quickly or in great quantity’.
[UK]N. Barlay Crumple Zone 2: The flakiest all-in under-sixteen bullshitters ever to skank off school and munch out on junk food.

2. (US campus) to kiss passionately.

[US]Eble Campus Sl. Nov.
munch the box (v.)

see sense 2 above.