symptom vs symptomatic

symptom is a noun but symptomatic is not a noun.

Word	Noun	Adjective	Verb	Adverb
symptom	Yes	No	No	No
symptomatic	No	Yes	No	No

symptom (noun)	symptomatic (noun)
anything that accompanies X and is regarded as an indication of X's existence
(medicine) any sensation or change in bodily function that is experienced by a patient and is associated with a particular disease

symptom (adjective)	symptomatic (adjective)
	relating to or according to or affecting a symptom or symptoms
	characteristic or indicative of a disease