Breadcrumb Home > Thesaurus > H Synonyms of heterostracan Find synonyms for: Noun 1. heterostracan, jawless vertebrate, jawless fish, agnathan usage: extinct jawless fish with the anterior part of the body covered with bony plates; of the Silurian and Devonian WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of heterostracan (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Chinese New Year History, Meaning, and Celebrations Current Events This Week: February 2024 Valentine's Day Valentine's Day History Mardi Gras 30 "Charlie and the Chocolate Factory" Quotes ✖ Related Content Daily Word Quiz: rococo Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language