knocker vs actor

knocker and actor both are nouns.

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

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

Other hypernyms of knocker include doer, worker.

knocker (noun)	actor (noun)
a device (usually metal and ornamental) attached by a hinge to a door	a theatrical performer
either of two soft fleshy milk-secreting glandular organs on the chest of a woman	a person who acts and gets things done
one who disparages or belittles the worth of something
a person who knocks (as seeking to gain admittance)
(Yiddish) a big shot who knows it and acts that way; a boastful immoderate person