'Pass' is a
Black American slang term. If a black person has light skin and
manageable hair, he or she may try to
pass as a
white person, in order to get a
job,
house, or
life that is more
desirable than what they could otherwise
expect.
To my knowledge, the term has become somewhat archaic after the advent of Affirmative Action and related programs, but some older African American citizens may still do this. I base this speculation on the fact that recent episodes of The PJs and Phillip Roth's book The Human Stain both make references to older black males that are passing.