soil vs foul

soil and foul both are nouns.

Word	Noun	Adjective	Verb	Adverb
soil	Yes	No	Yes	No
foul	Yes	Yes	Yes	No

As verbs, foul is a hyponym of soil; that is, foul is a word with a more specific, narrower meaning than soil:

Other hyponyms of soil include contaminate, pollute, smear, slime, muddy, muddy up, splash, mire, muck, muck up, mud, crock, blemish, spot.

soil (noun)	foul (noun)
the geographical area under the jurisdiction of a sovereign state	an act that violates the rules of a sport
material in the top layer of the surface of the earth in which plants can grow (especially with reference to its quality or use)
anything regarded as making something unclean
the part of the earth's surface consisting of humus and disintegrated rock

soil (adjective)	foul (adjective)
	(of a baseball) not hit between the foul lines
	disgustingly dirty; filled or smeared with offensive matter
	characterized by obscenity
	(of a manuscript) defaced with changes
	offensively malodorous
	highly offensive; arousing aversion or disgust
	especially of a ship's lines etc
	violating accepted standards or rules

soil (verb)	foul (verb)
make soiled, filthy, or dirty	become soiled and dirty
	make unclean
	spot, stain, or pollute
	make impure
	commit a foul; break the rules
	hit a foul ball
	become or cause to become obstructed