from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. An arrangement of spikes found on the tails of various stegosaurs.
Coined by Gary Larson in 1982. His comic strip shows a caveman giving a lecture illustrating this part of a dinosaur, with the caption "Now this end is called the thagomizer... after the late Thag Simmons". See -ize, -er. (Wiktionary)