nounC2Very rare — outside the 30,000 commonest English words, so you will meet it in writing rather than in speechToo rare in one of the two pools to compare — fewer than 20 uses in speech or in writing
A huge plant-eating dinosaur with a very long neck and tail.
Definitions of diplodocus
1noundiplodocusA huge plant-eating dinosaur with a very long neck and tail.C2