opinion vs fatwah

opinion and fatwah both are nouns.

Word	Noun	Adjective	Verb	Adverb
opinion	Yes	No	No	No
fatwah	Yes	No	No	No

As nouns, fatwah is a hyponym of opinion; that is, fatwah is a word with a more specific, narrower meaning than opinion:

opinion (noun)	fatwah (noun)
the reason for a court's judgment (as opposed to the decision itself)	(Islam) a legal opinion or ruling issued by an Islamic scholar
a personal belief or judgment that is not founded on proof or certainty
a belief or sentiment shared by most people; the voice of the people
a vague idea in which some confidence is placed
the legal document stating the reasons for a judicial decision
a message expressing a belief about something; the expression of a belief that is held with confidence but not substantiated by positive knowledge or proof