Green’s Dictionary of Slang

a despicable person.

1934		V.G. Burns Female Convict (1960) 45: Hey, lousy! Can that goddamn noise.
1951		J.D. Salinger Catcher in the Rye (1958) 148: The bartender was a lousy, too. He was a big snob.
1968		K. Brasselle Cannibals 92: The real guys in the business will have you marked lousy in spades.