n. In entomology, the grinding surface of a molar or broad basal tooth of the mandible.n. [capitalized] In ichthyology, the typical genus of plectognath fishes of the family called either Molidæ or Orthagoriscidæ, having as type the sunfish or head-fish, named Orthagoriscus mola by Bloch and Schneider, or M. rotunda of Cuvier and recent authors.