Activist and scholar Julia Serano defines cissexism as “the belief or assumption that cis people’s gender identities, expressions, and embodiments are more natural and legitimate than those of trans people.” It may be easier to break this concept down if you understand the pieces that make it up. The word cissexism is composed of two parts: the prefix “cis-” and the word “sexism.” “Cis” is derived from the term “cisgender.” Cisgender is a term used to describe someone who identifies with the sex and gender they were assigned at birth.