Green’s Dictionary of Slang

1. (orig. Aus.) to masturbate.

1984		Partridge DSUE (8th edn) 407/1: late C.19–20.
1990		Tupper & Wortley Aus. Prison Sl. Gloss. 🌐 Flip. 1. To masturbate.

2. (US) to hand over, to give.

1933		J. Spenser Limey 95: If I go and sob on his doorstep he’ll maybe flip me a couple o’ hundred bucks.
1960		J.D. Macdonald Slam the Big Door (1961) 123: I’m not flipping you a four-bit-piece to stop singing.

3. to make a sign; usu. in flip a/the bird under bird n.²

1982		(con. 1970) J.M. Del Vecchio 13th Valley (1983) 373: Peace marches [...] Everybody standin round flippin each other peace signs.
1982		J. Ellroy Clandestine 300: I [...] tripped over an old man, naked from the waist up [...] He cursed me and feebly flipped me the finger.

4. (US black) to make, to create, e.g. a marijuana cigarette, or a rap song.

1993		Source Dec. 43: It’s about being able to flip lyrics and beats they way they should be flipped.
2000		Ebonics Primer at www.dolemite.com 🌐 flip Definition: 1. to roll a blunt. [...] Example 1: Yo, who gonna flip the next el?