linguistic vs lingual

linguistic is not a noun while lingual is a noun.

Word	Noun	Adjective	Verb	Adverb
linguistic	No	Yes	No	No
lingual	Yes	Yes	No	No

As adjectives, linguistic and lingual are synonyms defined as:

linguistic (noun)	lingual (noun)
	a consonant that is produced with the tongue and other speech organs

linguistic (adjective)	lingual (adjective)
consisting of or related to language	consisting of or related to language
of or relating to the scientific study of language	pertaining to or resembling or lying near the tongue