funch, n. — Green’s Dictionary of Slang

funch n.

[fuck v. (1) + SE lunch; the trad. genteel term is euph. matinée n.]

sexual liaisons at lunchtime.

1972		B. Rodgers Queens’ Vernacular 91: funch (fr fag + lunch) brief sex act accomplished at noontime; a midday quickie.
1999		Roger’s Profanisaurus 3 in Viz 98 Oct. 14: funch n. Nooner; afternoon delight; To hide the salami during your dinner-time.
2004		Guardian G2 27 Sept. 16/3: His band of ‘frottagists’, ‘Roman-shower enthusiasts’, ‘Funchists’, ‘tromboners’ and ‘upper-deckers.’.