Lagomorph n. : One of the Lagomorpha.

Example:
What is the difference between a rodent and a Lagomorph?

Taxonomy
Genus, rodents, lagomorphs, pikas, order Lagomorpha, free encyclopedia, Infraclass, Kingdom Animalia, Phylum Chordata, Family Ochotonidae, Family Leporidae, late Paleocene, Superorder, eNature, Ochotona princeps, eastern Asia, Genus Ochotona, Genus Lepus.

Defination from the web:
lagomorphs are the members of the taxonomic order Lagomorpha, of which there are two families, the Leporidae (hares and rabbits), and the Ochotonidae (pikas) ... For a time it was common to consider the lagomorphs only distant relatives of the rodents, to whom they merely bore a ...