guinea pig vs actor

guinea pig and actor both are nouns.

Word	Noun	Adjective	Verb	Adverb
guinea pig	Yes	No	No	No
actor	Yes	No	No	No

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

guinea pig: a person who is subjected to experimental or other observational procedures; someone who is an object of investigation
actor: a person who acts and gets things done

Other hypernyms of guinea pig include doer, worker.

guinea pig (noun)	actor (noun)
stout-bodied nearly tailless domesticated cavy; often kept as a pet and widely used in research	a theatrical performer
a person who is subjected to experimental or other observational procedures; someone who is an object of investigation	a person who acts and gets things done