brontosaurus

noun

Etymology: From New Latin, from Ancient Greek roots; by surface analysis, bronto- + -saurus (“thunder lizard”), according to the notion that its massive size must have made its footsteps shake the ground.

1. Any of the genus †Brontosaurus of herbivorous sauropod dinosaurs with whip-like tails, which lived in present-day United States during the Late Jurassic period.

   “Near-synonym: thunder lizard (can denote a brontosaurus or an apatosaurus)”