gaywrites:

The word “cisgender” was officially added to the Oxford English Dictionary, proving that it’s truly working its way into modern usage and will become commonplace terminology before too long. 

The Oxford Dictionary (different from the OED) added the term cisgender in 2013, and in February 2014, Facebook included ten different cis- terms in its expanded gender-identity options. Yet people have been using cisgender for at least two decades. The Oxford Dictionary traces the evolution of the word to the ‘90s, and usage appears to go back to at least 1994, when a University of Minnesota biologist included the term in a post about a study on transphobia.

To be fair, the term was mostly confined to academic journals and online forums about gender issues until trans activist Julia Serano popularized it in her 2007 book, Whipping Girl. Serano says she started using the adjective after reading an essay by social-justice activist Emi Koyama, who wrote that terms like cisgender and cissexual are useful because “they de-centralize the dominant group, exposing it as merely one possible alternative rather than the ‘norm’ against which trans people are defined.”

Hey, this is important. Language matters.