riff-raff Definition

riff-raff
noun

1. derog
Worthless, disreputable or undesirable people, especially those considered to be of a low social class; the rabble.
Thesaurus: mob, masses, rabble, scum, undesirables, hoi polloi, the great unwashed (slang).

Etymology: 15c: as riff and raff one and all, from French from rifler to spoil + rafler to snatch away.