nonspeaking vs walk-on

nonspeaking is not a noun while walk-on is a noun.

Word	Noun	Adjective	Verb	Adverb
nonspeaking	No	Yes	No	No
walk-on	Yes	Yes	No	No

As adjectives, nonspeaking and walk-on are synonyms defined as:

nonspeaking and walk-on: not capable of or especially not involving speech or spoken lines

nonspeaking (noun)	walk-on (noun)
	plays a small part in a dramatic production

nonspeaking (adjective)	walk-on (adjective)
not capable of or especially not involving speech or spoken lines	not capable of or especially not involving speech or spoken lines