/ Dictionary / Index S sidero-: Meaning and Definition of Find definitions for: sidero- Pronunciation: [key] a combining form meaning “iron,” used in the formation of compound words: siderolite. sidero- Pronunciation: [key] a combining form meaning “star,” “constellation,” used in the formation of compound words: siderostat. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. siderite siderocyte 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