resid vs rock oil

resid and rock oil both are nouns.

Word	Noun	Adjective	Verb	Adverb
resid	Yes	No	No	No
rock oil	Yes	No	No	No

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

Other hypernyms of resid include crude, crude oil, fossil oil, oil, petroleum.

resid (noun)	rock oil (noun)
oil products that remain after petroleum has been distilled	a dark oil consisting mainly of hydrocarbons