Answer:
The way people view themselves as either male or female
Step-by-step explanation:
Gender expression is how a person expresses their gender in their clothes, haircut, with their body. One of the great struggles of the trans cause is that people stop associating an expression with a specific gender. For example, a trans man may wear dresses, have long hair, and wear so-called “feminine” clothes but continuing a trans man, just as a cis man can do that too. And cis and trans women can wear any clothes and have any hair and continue women. And the same goes for non-binaries, which may or may not look androgynous.
In short, the term gender refers to the way people see themselves as men or women.