The prefix cis- derives from the Latin term meaning “on this side of” or “on the same side as.” Linguistically, its use in English-speaking contexts dates back to the 17th century, when it was first used as a prefix signaling relative location. In this and within the sciences, it developed in implicit relation to trans-, meaning “across,” “through,” “on the other side of,” or “beyond.” The term cisgender circulated vernacularly within some trans communities before finding its way into print by the 1990s. It gained popularity by 2010 with the increasing publication of transgender scholarship and with greater trans visibility generally. Cisgender was added to the Oxford English Dictionary in 2016 and in Merriam-Webster’s dictionaries in 2017.

People began attaching cis- to the word gender in ...