sinistro- WORD ORIGIN a combining form meaning “left, on the left,” used in the formation of compound words: sinistrodextral.
Origin of sinistro- Latin sinistr-, stem of sinister (see) + Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019 sinistro- in Medicine sinistro- pref. Left:sinistral. Levorotatory:sinistrotorsion. The American Heritage® Stedman’s Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.