1) Genus of orthopterous insects 
Gryllus is a genus of field cricket (Orthoptera, Gryllidae, Gryllinae). Members of the genus are typically 15–31 mm long and darkly coloured. Until the mid-1950s, native field crickets in eastern North America were all assigned to a single species, Acheta assimilis Fabricius. Although regional variation in calling song and life history were note...
• (n.) A genus of insects including the common crickets.
Gryl'lus noun [ Latin , locust .] (Zoology) A genus of insects including the common crickets. 
Gryllus is a genus of orthopterous insects.