In the trans* community, to pass is to be perceived as the gender you identify as. It’s typically, but not always, used in the context of a trans* person discussing their experience in the public world. There’s some debate around the term in that it connotes that one is trying to pass under the radar as someone they aren’t when that isn’t the case.
“Passing” can be used in any context when dealing with perception. Someone can pass as white, as poor, as straight, as butch, etc.
“She passes really well despite not being on hormones.”
“It feels so good to pass and not be misgendered.”
“To be perceived as”