Green’s Dictionary of Slang

1. homosexual.

1942		‘Digg Mee’ ‘Observation Post’ in N.Y. Age 3 Jan. 9/8: Our town is getting to be a most peculiar place [...] There must be a ‘hex’ about that kinda sex.
1979		Maledicta III:2 217: Gay novelist John Rechy can still call queer a ‘curdling epithet’ and (the way peculiar used to be) queer is an artful force for conformity, increasingly used as we enter the neofascism of the eighties.

2. deranged, eccentric.

1978

P. Theroux Picture Palace 196: He was known as ‘peculiar’.