'Horntail' definitions:

Definition of 'Horntail'

From: GCIDE

Horntail \Horn"tail`\, n. (Zool.) Any one of family (Urocerid[ae]) of large hymenopterous insects, allied to the sawflies. The larv[ae] bore in the wood of trees. So called from the long, stout ovipositors of the females. [1913 Webster]