Definition of "Roach" :

noun: European freshwater food fish having a greenish back

noun: any of numerous chiefly nocturnal insects; some are domestic pests

noun: street names for flunitrazepan

noun: the butt of a marijuana cigarette

noun: a roll of hair brushed back from the forehead

verb: cut the mane off (a horse)

verb: comb (hair) into a roach