crude vs petroleum

crude and petroleum both are nouns.

Word	Noun	Adjective	Verb	Adverb
crude	Yes	Yes	No	No
petroleum	Yes	No	No	No

As nouns, crude and petroleum are synonyms defined as:

Other synonyms of crude include crude oil, fossil oil, oil, rock oil.

crude (noun)	petroleum (noun)
a dark oil consisting mainly of hydrocarbons	a dark oil consisting mainly of hydrocarbons

crude (adjective)	petroleum (adjective)
not refined or processed
belonging to an early stage of technical development; characterized by simplicity and (often) crudeness
conspicuously and tastelessly indecent
not processed or subjected to analysis
devoid of any qualifications or disguise or adornment
not carefully or expertly made