ailing vs unwell

ailing and unwell both are adjectives.

Word	Noun	Adjective	Verb	Adverb
ailing	No	Yes	No	No
unwell	No	Yes	No	No

As adjectives, ailing and unwell are synonyms defined as:

Other synonyms of ailing include indisposed, peaked, poorly, seedy, sickly, under the weather.

ailing (adjective)	unwell (adjective)
somewhat ill or prone to illness	somewhat ill or prone to illness