Breadcrumb Home > Thesaurus > S Synonyms of silurian Find synonyms for: Noun 1. Silurian, Silurian period usage: from 425 million to 405 million years ago; first air-breathing animals WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of silurian (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Hanukkah Origins of the Christmas Holiday Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 Krampus: The Christmas Devil Kwanzaa ✖ Related Content Daily Word Quiz: temporize Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language