unwell vs ailing

unwell and ailing both are adjectives.

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

As adjectives, unwell and ailing are synonyms defined as:

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

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