Noun

1. A black or brown straight-winged insect of the order Blattodea, with about 3,500 species divided into six families. Only a few of these take up residence with human beings. Among these are Periplaneta americana (American cockroach or palmetto bug); Blattella germanica (German cockroach or Croton bug); and Blattella asahinai (Asian cockroach).
2. Disparaging term for individuals or groups of people regarded as dirty, or who breed like cockroaches.