A person who is passing by (that is, walking past).

One who succeeds in passing a test, etc. / One who passes something along; a distributor. / (sports) Someone who passes, someone who makes a pass.

plural of passer-by

plural of passer

A pass or permit; a document permitting the bearer to travel, sometimes issued as an emergency passport.

plural of laissez-passer

plural of gas passer

(medicine, slang) An anesthesiologist.

plural of flat passer

(gambling, slang) A crooked die that is shaved down on certain sides to produce the desired rolls more frequently.