Islam vs monotheism

Islam and monotheism both are nouns.

Word	Noun	Adjective	Verb	Adverb
Islam	Yes	No	No	No
monotheism	Yes	No	No	No

As nouns, monotheism is a hypernym of Islam; that is, monotheism is a word with a broader meaning than Islam:

Islam: the monotheistic religious system of Muslims founded in Arabia in the 7th century and based on the teachings of Muhammad as laid down in the Koran
monotheism: belief in a single God

Islam (noun)	monotheism (noun)
the monotheistic religious system of Muslims founded in Arabia in the 7th century and based on the teachings of Muhammad as laid down in the Koran	belief in a single God
the civilization of Muslims collectively which is governed by the Muslim religion