stinking vs foul-smelling

stinking and foul-smelling both are adjectives.

Word	Noun	Adjective	Verb	Adverb
stinking	No	Yes	No	No
foul-smelling	No	Yes	No	No

As adjectives, stinking and foul-smelling are synonyms defined as:

Other synonyms of stinking include fetid, foetid, foul, funky, ill-scented, noisome, smelly.

stinking (adjective)	foul-smelling (adjective)
very bad	offensively malodorous
offensively malodorous