Green’s Dictionary of Slang

lunch n.

1. [1900s] (US) a certainty, e.g. in betting.

2. in food-related contexts.

(a) [1900s–10s] (US) the stomach.

(b) [1910s+] (US) the contents of the stomach; see lose (one’s) lunch under lose v.

(c) [1930s] (US) a lunch counter.

(d) [1950s+] something/someone who is about to suffer or be physically hurt, or is already ruined [is only good to serve as food for some large predator].

3. in sexual contexts.

(a) [1920s–30s] cunnilingus.

(b) [1970s+] (US gay) the bulge of the genitals under the trousers.

(c) see basket lunch under basket n.1

4. [1960s+] (US campus, also lunchie, lunchy) a dull, stupid person, a fool [i.e, one who is out to lunch adj.].

5. [2000s] a bonus, a profit [on the pattern of drink n.4 (2)].

SE in slang uses

In compounds

lunch bag (n.) (also lunchbox, lunch pail, lunchsack) [one who is out to lunch adj.; note OnLine Dict. of Playground Slang (2001): ‘from people who brought lunch to school in a bag, then went off to sit and eat it alone because no-one liked them’]

[1950s+] (US campus) a dull, foolish person, an undesirable person.

lunch-basket (n.) (also lunch-wagon)

[1910s] the stomach.

lunchbox (n.)

see separate entry.

lunch bucket (adj.)

1. [1950s+] (US) working-class, blue-collar [lunchpail ].

2. [1950s+] (US) stupid, dull, uninspiring [lunch bag ].

lunch counter (n.) (also lunchpails) [their provision of milk]

[1960s] (US) the female breasts.

lunch-grabber (n.)

[1900s-10s] (US) a hand.

lunch gut (n.)

[1950s+] (drugs) the vomiting that may follow an injection of heroin.

lunch-hooks (n.) [SE lunch hook, a hook used to remove meat from the pot]

1. [late 19C–1900s] (US campus) the teeth.

2. [late 19C+] (orig. US) the hand or fingers.

lunchmeat (n.)

1. [1970s+] (US campus) a stupid, contemptible person.

2. [1970s+] (US gay) the bulge of the genitals through the trousers.

3. [1980s+] (US) nonsense.

4. [1990s+] (US) a victim.

lunchpail (n.) (also lunchpailer) [metonymy]

1. [1950s+] (orig. US) a blue-collar worker; also attrib.

2. see lunch bag

In phrases

anti-lunch (n.) [either the drink is seen as counteracting one’s appetite or the sp. should be ante-]

[19C] an appetizer, a drink taken before lunch.

eat someone’s lunch (v.)

[1950s+] (US) to defeat, injure or outdo someone.

have someone for lunch (v.)

[1950s] to subject to intense pressure.

out to lunch (adj.)

see separate entry.