WordNet sense 1 (obscene terms for penis):

cock, dick, Peter, prick, shaft, tool, putz

WordNet sense 2 (bird with strong claws and a stiff tail adapted for climbing and a hard chisel-like bill for boring into wood for insects):

woodpecker, peckerwood

WordNet sense 3 (horny projecting mouth of a bird):

beak, bill, nib, neb