from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Any of various large, segmented aquatic arthropods of the order Eurypterida that existed from the Ordovician Period to the Permian Period.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A large, prehistoric, carnivorous arthropod, of the order Eurypterida, thought to be one of the first animals to venture onto land.
from The Century Dictionary and Cyclopedia
- n. A merostome crustacean of the family Eurypteridæ.
- Having the characters of or pertaining to Eurypterus or the Eurypteridæ.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. large extinct scorpion-like arthropod considered related to horseshoe crabs
From New Latin Eurypterida, order name, from Eurypterus, genus name : eury- + Greek pteron, wing; see -pter.(American Heritage® Dictionary of the English Language, Fourth Edition)