The earliest known gender-related use of the prefix in any language was in a 1914 German-language book on sexology, Lexikon des gesamten Sexuallebens by Ernst Burchard. According to the Oxford English Dictionary, the earliest use of the prefix in the context of gender in English dates from 1994.
- (geography) 'On this side of'.
- (chemistry) Forming names of chemical compounds in which two atoms or groups are situated on the same side of some plane of symmetry passing through the compound.
- (gender) Cis; cisgender or cissexual.
- (gender) Of, related to, or specific to cis persons.
- In the first sense, "on this side of", this prefix is usually attached directly to the word it modifies, or sometimes separated from it by a hyphen: cisrhenane, cis-Neptunian.
- In the gender-related senses, this prefix is attached directly to certain words, most notably cisgender and cissexual (which are almost always spelled thus, not as e.g. *cis sexual). In other cases, the related standalone adjective cis is used: hence one speaks of a cis perspective (not *cisperspective), etc. In particular, it is now sometimes considered offensive to write cisman or cis-man, the preferred spelling being cis man (cis man). Compare trans- and trans.