mid-14c., lousi, "infested with lice," from louse (n.) + -y (2). Figurative use as a generic adjective of abuse dates from late 14c.; sense of "swarming with" (money, etc.) is American English slang from 1843. Related: Lousiness.
a lousy play
burned their lousy clothes
a dirty (or lousy) trick
lounge
lounging
loupe
lour
louse
lousy
lout
loutish
louver
lovable
love