A stegosaurian dinosaur of the genus Stegosaurus of the Jurassic Period, having large upright plates along the back and two pairs of spikes on the tail. Also called stegosaur.
[New Latin Stegosaurus, genus name : Greek stegos, roof; see STEGODON + Greek sauros, lizard.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.