walk-on vs actor

walk-on and actor both are nouns.

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

As nouns, actor is a hypernym of walk-on; that is, actor is a word with a broader meaning than walk-on:

Other hypernyms of walk-on include histrion, player, role player, thespian.

walk-on (noun)	actor (noun)
plays a small part in a dramatic production	a theatrical performer
	a person who acts and gets things done

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