Source : Webster's Revised Unabridged Dictionary (1913)

Lousy \Lous"y\, a.
   1. Infested with lice.

   2. Mean; contemptible; as, lousy knave. [Vulgar]

Source : WordNet®

lousy
     adj 1: very bad; "a lousy play"; "it's a stinking world" [syn: {icky},
             {crappy}, {rotten}, {shitty}, {stinking}, {stinky}]
     2: infested with lice; "burned their lousy clothes"
     3: vile; despicable; "a dirty (or lousy) trick"; "a filthy
        traitor" [syn: {dirty}, {filthy}]
     [also: {lousiest}, {lousier}]