Green’s Dictionary of Slang

very unpleasant.

1969		S.C. Wilson Time Warp Tales [comic bk] Mixing it up with some mean ass foe buccaneers.
1974		V.E. Smith Jones Men 93: He’s a mean-ass little sucker.
1991		P. Cornwell Body of Evidence (1992) 127: Old Man Hunt who thinks his only kid’s a fuckin’ fairy because you’re not a mean-ass-son-of-a-bitch slumlord who don’t give a shit about anybody’s welfare or feelings.
2012		J. Díaz This Is How You Lose Her 32: Her moms was a mean-ass drunk.