Rabbits

• Formerly considered the suborder Duplicidentata of the order Rodentia
• Pikas
• Hares

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Lagomorpha \Lag`o*mor"pha\ (l[a^]g`[-o]*m[^o]r"f[.a]), prop. n. pl. [NL., fr. Gr. lagw`s a hare + morfh` form.] (Zo["o]l.) an order of rodent-like mammals, comprising the hares, rabbits, and pikas. They have four incisors in the upper jaw. Called also Duplicidentata ...

Wikipedia Word definitions in Wikipedia
The lagomorphs are the members of the taxonomic order Lagomorpha , of which there are two living families : the Leporidae ( hares and rabbits ) and the Ochotonidae (pikas). The name of the order is derived from the Ancient Greek lagos (λαγώς, "hare") + ...