Green’s Dictionary of Slang

flit v.1

[flit n.2 (1)]

to be a homosexual.

[US]Maledicta IX 177: Increasingly, the general public is hearing private language of films such as Outrageous […] there one heard words such as [...] suck-holes, drag queens, flitting, tacky, fruits, swishing, seafood (sailors), cruise, whore (as a verb).