n.
Pronunciation: ' pla-k ə - ˌ d ə rm
Function: noun
Etymology: New Latin Placodermi, ultimately from GK plak-, plax + derma skin ― more at DERM-
Date: circa 1865
: any of a class (Placodermi) of extinct chiefly Devonian fishes with an armor of bony plates and primitive jaw structures