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Definition of CIS

It is the abbreviated way to refer to a person who identifies as cisgender. This term was coined as a contrast to the word transgender and means “on the gender side”. That is, it identifies with the gender with which it was born.


Morpheme that is used to imply being next to something or someone or, also, being on the side here. Normally, it is used as a prefix in words like cismontano which is “on the side of the mountain”.


In chemistry, it refers to the fact that in a molecular structure there are two atoms “on the same side”. Generally, it refers to isomers.


The word cisgender (CIS) was introduced in 1991 by a German-born psychiatrist and sexologist named Volkmar Sigusch. The term is classified as a neologism that designates a person who fully identifies with his sexual phenotype.


Cis comes from the homograph and homophone Latin word cis and its use is fully accepted in the Spanish language. Its meaning is “next to” or “on the side of” and it is used in various ways in Spanish, usually as a prefix for words like “cismontano”, “cisandino” or “cisgender”.


A cis person is one who identifies his gender with the sex with which he was born. For example, if a person at birth was determined as a man and in his sexual maturity he feels identified with the masculine gender, this person can call himself cisgender or simply cis.

Someone cis could easily be homosexual , because, despite identifying as male or female, their sexual attraction may be inclined towards the same gender. Therefore, the terms cisgender and heterosexual cannot be understood as synonyms.