What does anon mean gay

In gay slang, anon means an unknown person. This is an abbreviation of the word anonymous, meaning that the person may not want their sexuality known publicly.
Commonly used terms include 'ANON' (anonymous), 'BB' (bareback), 'Bttm' (bottom), 'DL' (down low), 'FWB' (friends with benefits), 'LTR' (long-term relationship), and 'NSFW' (not safe for work).