castor oil vs physic

castor oil and physic both are nouns.

Word	Noun	Adjective	Verb	Adverb
castor oil	Yes	No	No	No
physic	Yes	No	No	No

As nouns, physic is a hypernym of castor oil; that is, physic is a word with a broader meaning than castor oil:

castor oil: a purgative extracted from the seed of the castor-oil plant; used in paint and varnish as well as medically
physic: a purging medicine; stimulates evacuation of the bowels

Other hypernyms of castor oil include aperient, cathartic, purgative.

castor oil (noun)	physic (noun)
a purgative extracted from the seed of the castor-oil plant; used in paint and varnish as well as medically	a purging medicine; stimulates evacuation of the bowels