repellent vs disgustful

repellent is a noun but disgustful is not a noun.

Word	Noun	Adjective	Verb	Adverb
repellent	Yes	Yes	No	No
disgustful	No	Yes	No	No

As adjectives, repellent and disgustful are synonyms defined as:

repellent and disgustful: highly offensive; arousing aversion or disgust

repellent (noun)	disgustful (noun)
the power to repel
a chemical substance that repels animals
a compound with which fabrics are treated to repel water

repellent (adjective)	disgustful (adjective)
incapable of absorbing or mixing with	highly offensive; arousing aversion or disgust
highly offensive; arousing aversion or disgust
serving or tending to repel