Definition from Wiktionary, the free dictionary
roach (plural roaches)
- A small freshwater fish in the carp family (Cyprinidae), Rutilus rutilus.
- (US) a cockroach.
- (US, slang, smoking) A butt of a marijuana cigarette.
- (UK, slang, smoking) The filter of a rolled cigarette or joint, made from card or paper.
- (nautical) An extra curve of material added to the leech edge of a sail to increase the sail area.
slang: butt of a marijuana cigarette
US: cockroach — see cockroach