neuralgy vs neuralgia

neuralgy and neuralgia both are nouns.

Word	Noun	Adjective	Verb	Adverb
neuralgy	Yes	No	No	No
neuralgia	Yes	No	No	No

As nouns, neuralgy and neuralgia are synonyms defined as:

neuralgy and neuralgia: acute spasmodic pain along the course of one or more nerves

neuralgy (noun)	neuralgia (noun)
acute spasmodic pain along the course of one or more nerves	acute spasmodic pain along the course of one or more nerves