gonna add my definition of cissexism from the notes here:
"cissexism it is the ideology which promotes the beliefs of:
gender being an oppositional binary between men and women,
gender being inherent/objective/unchanging,
people of certain genders having certain innate traits,
gender (identity/performance) should/must be socially and institutionally policed, and
cis people's experiences of gender are the most real and important and that trans experiences of gender must be able to be put into the boxes used by cis people in order to be real or meaningful.
"trans men have it easier than trans women because [cis] men of other marginalized groups have it easier than [cis] women" is an example of cissexism as it assumes that, amongst other things, trans men are an intersection of some vague "transness" and "manhood" as defined by cis men's experience with manhood, as opposed to being a socially unique gender position under patriarchy."
(note: I mostly left out intersex people from this definition because there exists the term "intersexism" for a reason. while both forms of sexism build off each other, & fundamentally cissexism is intersexist and intersexism is cissexist, i don't think its actually helpful, as an intersex person, to use any term (cissexism or exorsexism) that is primarily used by trans people to describe non-intersex-related trans issues, to describe intersex issues. intersexism is far more than one or two lone bullet points in a definition otherwise focused on gender and trans people as a group (including the majority of perisex trans people) and everyone should learn more about intersex activism and intersex terminology rather than simply trying to make intersex people a small part of terms and concepts that are not centering us when we desperately need that. sex and gender are constructs defined by each other but it is still useful to understand how they differ, especially when intersex people are constantly made into a side note on trans issues and people think that being a good trans ally automatically means you are a good intersex ally. tl;dr cissexism is inherently intersexist but that doesn't mean cissexism should be used to describe intersexism; instead we should talk about both and the inherent connective tissue that links them.)