admonitory vs warning

admonitory is not a noun while warning is a noun.

Word	Noun	Adjective	Verb	Adverb
admonitory	No	Yes	No	No
warning	Yes	Yes	No	No

As adjectives, admonitory and warning are synonyms defined as:

Other synonyms of admonitory include cautionary, exemplary, monitory.

admonitory (noun)	warning (noun)
	a message informing of danger
	cautionary advice about something imminent (especially imminent danger or other unpleasantness)
	notification of something, usually in advance

admonitory (adjective)	warning (adjective)
serving to warn	serving to warn
expressing reproof or reproach especially as a corrective