Cisgender

Cisgender is an adjective neologism used in the context of gender issues and counselling to refer to a type of gender identity formed by a match between an individual's biological sex and the behavior or role considered appropriate for one's sex. Cisgender exists in contrast to transgender on a bipolar spectrum of gender orientation.

Language
The word has its origin in the Latin-derived prefix cis, meaning "on the same side" as in the cis-trans distinction in chemistry. In this case, "cis" (on the same side) refers to the unity of a gender identity with a biological gender assignment.

Internet use
The word cisgender has been used on the internet since at least 1994, when it appeared in the alt.transgendered usenet group in a post by Dana Leland Defosse. Defosse does not define the term and seems to assume that readers are already familiar with it. Coinage has been attributed to Carl Buijs, a transsexual man from the Netherlands, in a number of internet publications. which suggest that he proposed the term in 1995. It may have been independently coined -- in April of 1996, Buijs said in a usenet posting "As for the origin; I just made it up".

Academic use
The term has more recently been used in scholarly publications, such as a 2006 article in the Journal of Lesbian Studies and Julia Serano's 2007 publication Whipping Girl. Serano also uses the related terms cissexual, which she defines as "people who are not transsexual and who have only ever experienced their subconscious and physical sexes as being aligned" (p. 12), and cissexism, "which is the belief that transsexuals' identified genders are inferior to, or less authentic than, those of cissexuals."