Green’s Dictionary of Slang

ammo n.

[abbr. + -o sfx (6)]

1. (also am, ami) ammunition; also attrib.

[UK]A.G. Empey Over the Top ‘Tommy’s Dict. of the Trenches’ 282: ‘Ammo’. Rifle ammunition. Used to add weight to Tommy’s belt. He carries 120 rounds, at all times, except when he buries it under the straw in his billet before going on a route march. In the trenches he expends it in the direction of Berlin.
[UK](con. WWI) Fraser & Gibbons Soldier and Sailor Words 6: Ammo, ammunition, e.g., Ammo depot, Ammo store, etc.
[US]J. Archibald ‘Crash on Delivery’ in Flying Aces Nov. [Internet] He stood near the ammo shack idly smoking a cigarette.
[UK]G. Kersh They Die with Their Boots Clean 2: There lies both scouts with knife-holes in their backs and their rifles and ammo gone.
[US]L. Uris Battle Cry (1964) 193: Danny [...] loaded up a couple of ammo clips.
[UK]R. Cook Crust on its Uppers 103: ’Ere’s the ammo for it.
[US]G.V. Higgins Friends of Eddie Coyle (1973) 21: You could get me some three-fifty-seven and forty-one ammo.
[Ire]J. Morrow Confessions of Proinsias O’Toole 38: We haven’t been lumbering him with duff ammo.
[US]S. King It (1987) 234: It was an ammo dump.
[Ire]R. Doyle Van (1998) 612: It’ll be ammo for yeh, compadre, Bertie’d said.
[UK]K. Sampson Powder 98: He’d handed her the pistol and a spare round of ammo for good measure.
[US]T. Dorsey Atomic Lobster 125: Nothing builds confidence like live ammo.
[Aus]L. Redhead Thrill City [ebook] How much ammo you got?
410 ‘Four Door Coming’ [lyrics] Mana got links for the am bits, might have to rob me a plug.
67 ‘Hookahs’ [lyrics] Ring ring, trap, trap, I phone up my bro, he got ami in packs.
[WI]Jamaica Obs. 14 Mar. [Internet] Four guns, ammo, saeized in 24 hours.

2. semen [fig. use of sense 1; note also earlier ammunition n. (1)].

[UK] ‘Lagos Lagoon’ in M. Page Kiss Me Goodnight, Sgt.-Major (1973) 56: He fired all his ammo while well out of range.

3. (US Und.) money [fig. use of sense 1].

[US]H. Hill A Good Fella’s Guide To N.Y. 123: Candy, markers, ammo, liners, stocking stuffer, sweetener, garnish, and pledges are all terms for cash.