cis-

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).

Origin of cis-

< Latin; akin to here

Words nearby cis-

cis female, cis male, cis man, cis person, cis woman, cis-, cis-aconitic acid, cis-trans test, cisaconitic acid, cisalpine, cisalpine gaul

British Dictionary definitions for cis-

cis-

prefix

on this or the near side of cisalpine
(often in italics) indicating that two groups of atoms in an unsaturated compound lie on the same side of a double bond cis- butadiene Compare trans- (def. 5)

Word Origin for cis-

from Latin

Medical definitions for cis-

cis-

pref.

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.