Green’s Dictionary of Slang

1. (US) showy, slick, saucy, impertinent, ostentatious, attractive.

1896		H. Blossom Checkers 43: My money made me kind of ‘flossy,’ and whenever I’d feel like it, I’d just throw up the job and quit.
1896		W.C. Gore Student Sl. in Cohen (1997) 13: flossy a. Beautiful, stylish.
1900		Ade More Fables in Sl. (1960) 152: He’d show you if you could get Flossy with a lady.
1905		H. Green Actors’ Boarding House (1906) 81: She wasn’t a bad looker, though with the flossy rags off she wouldn’t stack up so well.
1912		S. Ford Odd Numbers 96: It’s most too bad, your wastin’ all this flossy talk on me, who can’t appreciate its fine points.
1913		Sun (Kalgoorlie, WA) 27 July 8/6: [US speaker] ‘Whenever [an Australian girl] flashes her flossy mush on us, it’s an upper-cut to the heart’.
1919		Van Loan ‘Nine Assists & Two Errors’ in Score by Innings (2004) 409: He waltzed up to the desk and said he wanted the best suite in the house [...] Flossy-looking boy – eh?
1920		Ade Hand-made Fables 112: The Migrator carried a flossy Label. He had been christened Adelbert Justitian.
1922		Broadway Brevities Aug. 44/1: After being close pals so long, why allow a flossy little blonde to start trouble.
1932		‘R. Scully’ Scarlet Pansy 264: Mrs. Slatternly, who wished to justify her yen for flossy gentlemen, became profound.
1943		C. McCullers Heart is a Lonely Hunter (1986) 218: The bedroom was done over [...] Before it had been tacky and flossy and drab.
1953		R. Chandler Long Good-Bye 95: So I called a man I knew in the Carne Organisation, a flossy agency in Beverly Hills that specialized in protection for the carriage trade.
1963		B. Hecht Gaily, Gaily 87: He presided here nightly, respected and admired by Chicago’s flossiest citizens.
1970		E. Tidyman Shaft 37: The flossy midtown health clubs.
1981		J. Wambaugh Glitter Dome (1982) 43: Baby, do you think you have any lipstick left on your mouth after three or four of those flossy fatcats from Brentwood with those little limp peters make you suck your eyes crossed?
2003		A. Newitz ‘Bay Area Sl.’ on Berkeley University Amer. Studies 102 Course Website 🌐 Flossy – Showing off. Derivitive of flossing your teeth.

2. of homosexuals, flagrant, ostentatious.

1965		Guild Dict. Homosexual Terms 16: flossy (adj.): An effeminate homosexual, as applied by the heterosexual. (Very rare.).
1972		B. Rodgers Queens’ Vernacular 73: stereotype effeminate homosexual [...] flossy one.