sphecoid Any of various solitary wasps; such as: Mason wasp, a wasp that constructs nests of hardened mud or clay for the young. Digger wasp, a wasp that digs nests in the soil and stocks them with paralyzed insects for the larvae. Mud dauber, a wasp that constructs mud cells on a solid base in which females place eggs laid in paralyzed insect l... Found on http://www.wordinfo.info/words/index/info/view_unit/1997/