-ˈtrōd.əs noun
Usage: capitalized
Etymology: New Latin, from Greek strongylos round, compact + kentrōtos prickly, from kentroun to provide with a prick or sting, from kentron sharp point — more at strongylus , center
: a widely distributed genus of sea urchins (family Strongylocentrotidae) that includes the common green urchin ( S. drobachiensis ) of the No. American coasts and the small purple urchin ( S. purpuratus ) of the Pacific coast as well as other common forms