Definition of mouse hawk in US English:

mouse hawk

noun

  • A bird of prey that catches mice; especially †(a) the short-eared owl, Asio flammeus (obsolete); (b) US the hen harrier, Circus cyaneus; (c) US the rough-legged buzzard, Buteo lagopus (rare).

Origin

Old English; earliest use found in Corpus Glossary. From mouse + hawk.

Pronunciation

mouse hawk

/ˈmaʊs hɔːk/