Green’s Dictionary of Slang

sexual intercourse; often found in pidgin slangs.

1918		A.W. Scherr diary 18 Feb. 🌐 More celebrating by Pinkey and Si. both got zig-zag.
1918		H.V. O’Brien diary 30 Jan. in Wine, Women and War (1926) 18: All but raped. Zig-zig – nothing else but.
1930		(con. 1915) ‘W.W. Windstaff’ ‘A Flier’s War’ in Longstreet Canvas Falcons (1970) 271: Uloo, Tommy. Zig-zig wif me?
1946		J.W. Bishop ‘American Army Speech’ in AS XXI:4 Dec. 249: Question: Did you actually hear the accused talking French to this girl? Answer: Yes, sir. Q: Well, what did he say, if you know? A: He said, ‘No zig-zig ce soir, sweetheart.’.
1962		P. Crump Burn, Killer, Burn! 158: Zigg, zigg, mademoiselle, down to the mezzanine, oui?
1965		L. Haylen Big Red 186: Blackfellow no read [...] Only short words like axe, tree and grub and ziggy-zig, pom-pom!
1970		T. Southern Blue Movie (1974) 166: Make real love, yes. Intercourse, right? Zig-zig, right? Fuck-fuck, right?
1989		(ref. to WWI) H. Rawson Dict. of Invective (1991) 433: zig-zig. To copulate and the act of doing so; a French expression, acquired by U.S. servicemen in World War I and reacquired in World War II.