spoilage vs mildew

spoilage and mildew both are nouns.

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

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

Other hyponyms of spoilage include mold, mould, souring.

spoilage (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
the amount that has spoiled

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