quadruped (n.) Look up quadruped at Dictionary.com
1640s, from French quadrupède (16c.), from Latin quadrupes (genitive quadrupedis) "four-footed, on all fours," also, as a noun, "a four-footed animal," from quadri- "four" (from PIE root *kwetwer- "four") + pes "foot" (from PIE root *ped- "foot"). The adjective is attested from 1741. Related: Quadrupedal (1610s).