Green’s Dictionary of Slang

(US black) admirable, excellent.

1964		B. Jackson Get Your Ass in the Water (1974) 93: With your connections fair and your hustlin’ girls is square, / you was the dapperest stud on the scene.
1999		Guardian G2 16 July 8: Busta Rhymes [...] the dapper rapper.
2002		‘Touré’ Portable Promised Land (ms.) 153: We Words (My Favorite Things) [...] Threads. Dapper. Dipped. Clean. Sharp. Diva. Playa. Fly girl. Fly guy.