WordReference Random House Unabridged Dictionary of American English © 2026
di•met•ro•don
(dī me′trə don′),USA pronunciation n.
- Paleontologyan extinct carnivorous mammallike reptile, of the genus Dimetrodon, dominant in North America during the Permian Period, up to 10 ft. (3.1 m) long and usually bearing spinal sails.
- Neo-Latin (1878), equivalent. to Greek dímetr(os) having two measures (see dimeter) + odó̄n tooth; apparently so named in reference to the large size of the anterior incisors relative to the other teeth