'Digger wasp' definitions:

Definition of 'digger wasp'

noun

Solitary wasp that digs nests in the soil and stocks them with paralyzed insects for the larvae

From: GCIDE

Wasp \Wasp\, n. [OE. waspe, AS. w[ae]ps, w[ae]fs; akin to D. wesp, G. wespe, OHG. wafsa, wefsa, Lith. vapsa gadfly, Russ. osa wasp, L. vespa, and perhaps to E. weave.] (Zool.) Any one of numerous species of stinging hymenopterous insects, esp. any of the numerous species of the genus Vespa, which includes the true, or social, wasps, some of which are called yellow jackets. [1913 Webster]
Note: The social wasps make a complex series of combs, of a substance like stiff paper, often of large size, and protect them by a paperlike covering. The larvae are reared in the cells of the combs, and eat insects and insect larvae brought to them by the adults, but the latter feed mainly on the honey and pollen of flowers, and on the sweet juices of fruit. See Illust. in Appendix. [1913 Webster]
Digger wasp, any one of numerous species of solitary wasps that make their nests in burrows which they dig in the ground, as the sand wasps. See Sand wasp, under Sand.
Mud wasp. See under Mud.
Potter wasp. See under Potter.
Wasp fly, a species of fly resembling a wasp, but without a sting. [1913 Webster] [1913 Webster]

From: GCIDE