racial passing

Racial passing is presenting oneself as a member of a different racial group than one's ancestry would suggest, historically most often a light-skinned Black person living as white.

The practice was most common in the United States during segregation, when passing could mean access to jobs, housing, and safety otherwise denied.

Her grandmother had passed for white her entire adult life.

The term now extends to other contexts where someone is perceived as belonging to a group they don't identify with.