1) Family crotalidae 2) Reptile family 
<herpetology> A family of New World vipers characterised by the presence of a heat-sensitive loreal pit between each eye and nostril, and folding, caniculated, long anterior fangs. ... (05 Mar 2000) ... 
Type: Term Pronunciation: krō-tal′i-dē Definitions: 1. A family of New World vipers characterized by the presence of a heat-sensitive loreal pit between each eye and nostril, and folding, caniculated, long anterior fangs.
Crotalidae is the 'Pit Vipers' sub-family of reptiles of the sub-order Serpentes (Snakes) comprising some seven genera and 130 species native mainly to the Americas with some found in south and south-east Asia. The members have a large, often triangular head which is distinct from a robust body by a relatively narrow neck. The members are character...
[n] - New World vipers: pit vipers
family Crotalidae noun New World vipers: pit vipers