As nouns,
vespertilionid is a hypernym of
Pipistrellus pipistrellus; that is, vespertilionid is a
word with a broader meaning than Pipistrellus pipistrellus:
Pipistrellus pipistrellus: small European brown bat
vespertilionid: a variety of carnivorous bat
Other hypernyms of Pipistrellus pipistrellus include
vespertilian bat.