watcher vs actor

watcher and actor both are nouns.

Word	Noun	Adjective	Verb	Adverb
watcher	Yes	No	No	No
actor	Yes	No	No	No

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

watcher: a person who keeps a devotional vigil by a sick bed or by a dead body
actor: a person who acts and gets things done

Other hypernyms of watcher include doer, worker.

watcher (noun)	actor (noun)
a guard who keeps watch	a theatrical performer
a close observer; someone who looks at something (such as an exhibition of some kind)	a person who acts and gets things done
a person who keeps a devotional vigil by a sick bed or by a dead body