stinky vs ill-smelling

stinky and ill-smelling both are adjectives.

Word	Noun	Adjective	Verb	Adverb
stinky	No	Yes	No	No
ill-smelling	No	Yes	No	No

As adjectives, stinky and ill-smelling are synonyms defined as:

Other synonyms of stinky include malodorous, malodourous, unpleasant-smelling.

stinky (adjective)	ill-smelling (adjective)
having an unpleasant smell	having an unpleasant smell
very bad