people, or a group of people, regarded as disreputable or worthless: a pack of riffraff.
2.
the lowest classes; rabble: the riffraff of the city.
3.
trash; rubbish.
–adjective
4.
worthless, disreputable, or trashy.
Origin: 1425–75; late ME rif and raf every particle, things of small value < OF rif et raf, formed on rifler to spoil (see rifle2), raffler to ravage, snatch away
[Middle English riffe raffe, from rif and raf, one and all, from Anglo-Norman rif et raf, rifle et rafle : Old French rifler, to rifle; see rifle2 + Old French raffler, to carry off (from raffle, act of seizing; see raffle1).]
c.1470, from earlier rif and raf "one and all, every scrap" (1338), from O.Fr. rif et raf, from rifler "to spoil, strip" (see rifle (v.)) and raffler "carry off," related to rafle "plundering" (see raffle).