missing, adj. — Green’s Dictionary of Slang

missing adj.

[note the phr. be missing, used first used by Chicago mobster Spike O’Donnell in rejecting the overtures/threats of Al Capone (1899–1947); also Schele de Vere, Americanisms (1872): ‘Missing, to be found, denotes, in Western parlance, to be absent, or to run away’]

absent, departed.

[1821		Egan Life in London (1830) 45: It was expedient that he should [...] if necessary, be ‘missing’ before his antagonist had recovered the use of his pins].
1958		F. Norman in Vogue Oct. in Norman’s London (1969) 33: He [...] gave us the slingers on the spot saying if we wasn’t missing in ten minutes he would call the law.
1997		C. Newland Scholar 77: I’ve heard enough of dis shit, I’m missin’.
2001		(con. 1981) A. Wheatle East of Acre Lane 238: ‘Why don’t I call Biscuit [...].’ ‘No! Do dat an’ I’m missing, believe.’.
2016		A. Wheatle Crongton Knights 43: ‘I’m missing, sis’.