walker vs passer

walker and passer both are nouns.

Word	Noun	Adjective	Verb	Adverb
walker	Yes	No	No	No
passer	Yes	No	No	No

As nouns, passer is a hyponym of walker; that is, passer is a word with a more specific, narrower meaning than walker:

walker (noun)	passer (noun)
an enclosing framework on casters or wheels; helps babies learn to walk	(football) a ball carrier who tries to gain ground by throwing a forward pass
a light enclosing framework (trade name Zimmer) with rubber castors or wheels and handles; helps invalids or the handicapped or the aged to walk	a person who passes by casually or by chance
a shoe designed for comfortable walking	a student who passes an examination
a person who travels by foot	a person who passes as a member of a different ethnic or racial group