- roach - the butt of a marijuana cigarette
--1 is a kind of butt, stub
- R-2, Mexican valium, rophy, rope, roofy, roach, forget me drug, circle - street names for flunitrazepan
--2 is a kind of flunitrazepan, Rohypnol
- cockroach, roach - any of numerous chiefly nocturnal insects; some are domestic pests
--3 is a kind of dictyopterous insect
--3 is a member of Blattodea, suborder Blattodea, Blattaria, suborder Blattaria
--3 has particulars:- roach, Rutilus rutilus - European freshwater food fish having a greenish back
--4 is a kind of cyprinid, cyprinid fish
--4 is a member of Rutilus, genus Rutilus - R-2, Mexican valium, rophy, rope, roofy, roach, forget me drug, circle - street names for flunitrazepan