Ingerman vs Ingrian

Ingerman and Ingrian both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ingerman	Yes	No	No	No
Ingrian	Yes	No	No	No

As nouns, Ingerman and Ingrian are synonyms defined as:

Ingerman and Ingrian: a member of western Finnish people formerly living in the Baltic province where Saint Petersburg was built

Other synonyms of Ingerman include Inger.

Ingerman (noun)	Ingrian (noun)
a member of western Finnish people formerly living in the Baltic province where Saint Petersburg was built	a Finnic language spoken by the Ingrian
	a member of western Finnish people formerly living in the Baltic province where Saint Petersburg was built