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Definition of placoderm

placoderm

/ˈplæk.əˌdɜːrm/
plac · o · derm
Plural:placoderms
•
Adjective:placodermal
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placoderm Lexical Profile

placoderm Game Scores & Validity

• noun

1

An extinct jawed fish of the class Placodermi, prevalent during the Silurian and Devonian periods, characterized by a heavily armored head and thorax made of articulated bony plates.

Example

"Dunkleosteus is one of the most famous and formidable placoderms, known for its massive size and powerful, self-sharpening jaw plates."

• Rhymes for placoderm

• Nearby Words

placid
placidity
placidly
placoderm
plagianthus
plagiarism
plagiarist

Word Origin & Etymology

Coined in the mid-19th century from Greek 'plax' or 'plak-' (flat plate) and 'derma' (skin), referring to the protective bony plates covering the heads and thoraxes of these prehistoric fish.

Usage Trend

Historical frequency of usage in published text.

180019102020
Data source: Google Books Ngram Viewer

Cite this Entry

Wordmom. (2026). Definition of Placoderm. In Wordmom Dictionary. Retrieved Nov 6, 2026, from https://wordmom.com/dictionary/placoderm
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