Of or belonging to the Vespertilionidæ, a large family of insectivorous bats, including the common British species. Also as n., a bat of this family.

Of or belonging to, comprising or consisting of, a large distinct group of insectivorous bats included in the sub-order Microchiroptera.

Of or relating to the genus Plecotus of bats of the family Vespertilionidae, characterized by very large ears and glandular masses on the muzzle.