a member of the family Cerambycidae, which are phloem borers —note 1. neither the larvae nor the adults of roundheaded borers have round heads; the term may refer to the round emergence holes of some species —note 2. some species of roundheaded borers are important pests, e.g., the southern pine sawyer, Monochamus titillator —synonym roundheaded phloem borer —see flatheaded borer This definition last updated 08/17/2008