- a combining form meaning “iron,” used in the formation of compound words: siderolite.
Also especially before a vowel, sider-.
Origin of sidero-1
< Greek sidēro-, combining form of sídēros iron
- a combining form meaning “star,” “constellation,” used in the formation of compound words: siderostat.
Origin of sidero-2
< Latin sīder- (stem of sīdus) star-group + -o-
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
before a vowel sider-
- indicating ironsiderolite
from Greek sidēros
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.