Meaning

adjective marked by up-to-dateness in dress and manners

adjective marked by a carefree unconventionality or disreputableness; - Crary Moore

originFrom late 18th century raff (“persons among the lowest class in society”) + -ish, still retained in contemporary English with riffraff. From Old French raffer (“to wear away”), of Germanic origin. Compare German raffen. Compare rip (“to tear”), rap (“to snatch”).

Etymology from Wiktionary, CC BY-SA 3.0