Shiah vs Shia

Shiah and Shia both are nouns.

Word	Noun	Adjective	Verb	Adverb
Shiah	Yes	No	No	No
Shia	Yes	No	No	No

As nouns, Shiah and Shia are synonyms defined as:

Shiah and Shia: one of the two main branches of orthodox Islam; mainly in Iran

Other synonyms of Shiah include Shiah Islam.

Shiah (noun)	Shia (noun)
one of the two main branches of orthodox Islam; mainly in Iran	one of the two main branches of orthodox Islam; mainly in Iran