From Wikipedia, the free encyclopedia. Cisgender (often abbreviated to simply cis) is a characteristic of people having a gender identity that matches the sex that they were assigned at birth. Cisgender may also be defined as those who have a gender identity or perform a gender role society considers appropriate for one's sex.. It is the opposite of the term transgender. There are two versions of the term: cis male for male assigned male at birth or cis female for female assigned female at birth.