noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   Any of the armored jawless fishes of the Paleozoic.
2. 2
   extinct fish-like jawless vertebrate having a heavily armored body; of the Paleozoic wordnet

Etymology

From New Latin ostracum, from Ancient Greek ὄστρακον (óstrakon, “pottery fragment; shell”) + δέρμα (dérma, “skin”).

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.