domino!, excl. — Green’s Dictionary of Slang

domino! excl.

[the game of dominoes, in which the winner is the player who gets rid of all their pieces first]

a general excl. to signify the end of or last of a situation: that’s it, that’s done, all over etc; esp. among soldiers and sailors, to signify the last blow of a thrashing; thus it is domino with..., it is finished, it is all over, it is hopeless.

1864, 1867, 1870		Hotten Sl. Dict. 123: domino a common ejaculation of soldiers and sailors when they receive the last lash of a flogging.
1873		Sl. Dict.
1895		Crowe Aus. Sl. Dict. 24: Domino, the last lash of a flogging.
1911		A. Bennett Card (1974) 265: Appendicitis, of course. Operation – domino! All over in three days.
1967		M. Braly On the Yard (2002) 107: I even got religion once. I steady schemed on that church [...] Domino, they gave me a parole behind it.