1. any of several New World tropical bats of the genera Desmodus, Diphylla, and Diaemus, the size of a small mouse, feeding on small amounts of blood obtained from resting mammals and birds by means of a shallow cut made with specialized incisor teeth.
2. any of several large South American bats of the genera Phyllostomus and Vampyrus, erroneously believed to feed on blood.
3. See false vampire .
[ 1780-90 ]