/ Dictionary / Index S Silurian: Meaning and Definition of Find definitions for: Si•lu•ri•an Pronunciation: (si-loor'ē-un, sī-), [key] — adj. of or pertaining to the Silures or their country. noting or pertaining to a period of the Paleozoic Era, occurring from 425 to 405 million years ago, notable for the advent of air-breathing animals and terrestrial plants. See table under —n. the Silurian Period or System of rocks. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: silurian (Thesaurus) Silures silurid Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language