spoiling vs mildew

spoiling and mildew both are nouns.

Word	Noun	Adjective	Verb	Adverb
spoiling	Yes	No	No	No
mildew	Yes	No	Yes	No

As nouns, mildew is a hyponym of spoiling; that is, mildew is a word with a more specific, narrower meaning than spoiling:

Other hyponyms of spoiling include mold, mould, souring.

spoiling (noun)	mildew (noun)
the act of spoiling something by causing damage to it	a fungus that produces a superficial (usually white) growth on organic matter
the process of becoming spoiled	the process of becoming mildewed

spoiling (verb)	mildew (verb)
	become moldy; spoil due to humidity