imam vs Muslim

imam and Muslim both are nouns.

Word	Noun	Adjective	Verb	Adverb
imam	Yes	No	No	No
Muslim	Yes	Yes	No	No

As nouns, Muslim is a hypernym of imam; that is, Muslim is a word with a broader meaning than imam:

imam: (Islam) the man who leads prayers in a mosque; for Shiites an imam is a recognized authority on Islamic theology and law and a spiritual guide
Muslim: a believer in or follower of Islam

Other hypernyms of imam include leader, Moslem.

imam (noun)	Muslim (noun)
(Islam) the man who leads prayers in a mosque; for Shiites an imam is a recognized authority on Islamic theology and law and a spiritual guide	a believer in or follower of Islam

imam (adjective)	Muslim (adjective)
	of or relating to or supporting Islamism