Green’s Dictionary of Slang

a general term of abuse.

1905		‘Hugh McHugh’ Get Next 16: He has trained these twelve skeets to sing ‘Zobia Grassa’.
1937		E. Anderson Thieves Like Us (1999) 122: Well, I’m no damned soda skeet making ten dollars a week.
1985		J. Wambaugh Secrets of Harry Bright (1986) 232: They’d just told a Jew joke [...] and were into the second spook joke about the black sky divers in Texas being called skeet.