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Webster 1913 Edition
Eurypteroid
Eu-ryp′ter-oid
,Adj.
 [
Eurypterus 
+ -oid
.] (Paleon.) 
Like, or pertaining to, the genus Euryperus. 
Definition 2025
eurypteroid
eurypteroid
English
Adjective
eurypteroid (not comparable)
- (paleontology) Like, or pertaining to, the genus Eurypterus.