If you've ever seen Jurassic Park, you know that dinosaurs were large reptilian creatures that walked the earth during the Mesozoic era that ran from 245 million to 68 million years ago and included the Triassic, Jurassic, and Cretaceous periods.

The ancient Greeks had no knowledge of dinosaurs that we know of, but they unknowingly contributed to the word dinosaur. It was cobbled together in 1841 by British scientist Sir Richard Own, using the words deinos, meaning "terrible" and sauros meaning "lizard." All are goneā€”at least in their original form, although it is thought they simply evolved into other, present-day animals. The word dinosaur is often used for someone who is old-fashioned or unable to adapt to modern times.

Definitions of dinosaur

n any of numerous extinct terrestrial reptiles of the Mesozoic era

show 17 types...
hide 17 types...
ornithischian, ornithischian dinosaur
herbivorous dinosaur with a pelvis like that of a bird
massive herbivorous bipedal dinosaur with a long heavy tail; common in Europe and northern Africa; early Cretaceous period
saurischian, saurischian dinosaur
herbivorous or carnivorous dinosaur having a three-pronged pelvis like that of a crocodile
a huge quadrupedal herbivore with long neck and tail; of late Jurassic in western North America
titanosaur, titanosaurian
amphibious quadrupedal herbivorous dinosaur with a long thin neck and whiplike tail; of the Cretaceous mostly in the southern hemisphere
huge herbivorous dinosaur of Cretaceous found in Argentina
ground-shaker, seismosaur
huge herbivorous dinosaur of the Cretaceous found in western North America
pisanosaur, pisanosaurus
primitive dinosaur found in Argentina
staurikosaur, staurikosaurus
primitive dinosaur found in Brazil
armored dinosaur
dinosaurs having bony armour
bone-headed dinosaur
bipedal herbivorous dinosaurs with bony crowns
ceratopsian, horned dinosaur
any of several four-footed herbivorous dinosaurs with enormous beaked skulls; of the late Cretaceous in North America and Mongolia
ornithopod, ornithopod dinosaur
bipedal herbivorous dinosaur
duck-billed dinosaur, hadrosaur, hadrosaurus
any of numerous large bipedal ornithischian dinosaurs having a horny duck-like bill and webbed feet; may have been partly aquatic
sauropod, sauropod dinosaur
very large herbivorous dinosaur of the Jurassic and Cretaceous having a small head a long neck and tail and five-toed limbs; largest known land animal
genus Argentinosaurus
enormous dinosaur of the middle Cretaceous found in Argentina
bird-footed dinosaur, theropod, theropod dinosaur
any of numerous carnivorous dinosaurs of the Triassic to Cretaceous with short forelimbs that walked or ran on strong hind legs
Type of:
archosaur, archosaurian, archosaurian reptile
extinct reptiles including: dinosaurs; plesiosaurs; pterosaurs; ichthyosaurs; thecodonts

Sign up, it's free!

Whether you're a student, an educator, or a lifelong learner, Vocabulary.com can put you on the path to systematic vocabulary improvement.