‖n. [ NL., fr. Gr. &unr_; terrible + &unr_;, &unr_;, horn. ] (Paleon.) A genus of large extinct Eocene mammals from Wyoming; -- called also Uintatherium. See Illustration in Appendix. [ 1913 Webster ]

☞ They were herbivorous, and remarkable for three pairs of hornlike protuberances on the skull. The males were armed with a pair of powerful canine tusks. [ 1913 Webster ]

n. a small order of primitive ungulates of the Paleocene and Eocene.
Syn. -- order Dinocerata. [ WordNet 1.5 ]

n. and order of plankton, in some classifications it is considered a phylum of the kingdom Protista; in others it is included in the plant phylum Pyrrophyta. Its members usually have two flagella, one of which extends from its center.
Syn. -- order Dinoflagellata, Cilioflagellata, order Cilioflagellata. [ WordNet 1.5 +PJC ]

n. a member of the Dinoflagellata, chiefly marine protozoa having two flagella. The dinoflagellates form a chief constituent of plankton. [ WordNet 1.5 ]

‖n. [ NL., fr. Gr. &unr_; terrible + &unr_; bird. ] (Paleon.) A genus of extinct, ostrichlike birds of gigantic size, which formerly inhabited New Zealand. See Moa. [ Written also Deinornis. ]

‖n. pl. [ NL., fr. Gr. &unr_; terrible + &unr_; lizard. ] (Paleon.) An order of extinct mesozoic reptiles, mostly of large size (whence the name). Notwithstanding their size, they present birdlike characters in the skeleton, esp. in the pelvis and hind limbs. Some walked on their three-toed hind feet, thus producing the large “bird tracks, ” so-called, of mesozoic sandstones; others were five-toed and quadrupedal. See Illust. of Compsognathus, also Illustration of Dinosaur in Appendix.

{ } n. [ Gr. &unr_; terrible + &unr_; lizard. ] (Paleon.) One of the Dinosauria. [ Written also deinosaur, and deinosaurian. ] [ 1913 Webster ]

{ ‖ } n. [ NL. dinotherium, fr. Gr. deino`s terrible + qhri`on beast. ] (Paleon.) A large extinct proboscidean mammal from the miocene beds of Europe and Asia. It is remarkable for a pair of tusks directed downward from the decurved apex of the lower jaw. [ 1913 Webster ]

n. (Chem.) Same as Dioxide. [ 1913 Webster ]