Entry 1 sense Webster, 1913 Cockroach /käk'-rōchˌ/ · Cock·roach · IPA /ˈkɑkɹoʊt͡ʃ/ 01 n. An orthopterous insect of the genus Blatta, and allied genera. 1. An orthopterous insect of the genus Blatta, and allied genera.(Zool.)