a prefix occurring in loanwords from Latin meaning “on the near side of; on this side of” (cisalpine); on this model, used in the formation of compound words (cisatlantic).
Chemistry. a specialization of this denoting a geometric isomer having a pair of identical atoms or groups attached on the same side of two atoms linked by a double bond.Compare trans-(def 2).
a prefix meaning “on the same side of,” referring to the alignment of one’s gender identity with one’s biological sex assigned at birth (cisgender; cissexual).
cisRead more in this article about some frequently asked questions and fun facts related to our definitions.
Origin of cis-
< Latin; akin to here
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for cis-
on this or the near side ofcisalpine
(often in italics) indicating that two groups of atoms in an unsaturated compound lie on the same side of a double bondcis- butadiene Compare trans- (def. 5)
Word Origin for cis-
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Medicine definitions for cis-
Having a pair of identical atoms or groups on the same side of a plane that passes through two carbon atoms linked by a double bond:cis-butene.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.