sustenance vs milk

sustenance and milk both are nouns.

Word	Noun	Adjective	Verb	Adverb
sustenance	Yes	No	No	No
milk	Yes	No	Yes	No

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

sustenance (noun)	milk (noun)
the act of sustaining life by food or providing a means of subsistence	produced by mammary glands of female mammals for feeding their young
a source of materials to nourish the body	a white nutritious liquid secreted by mammals and used as food by human beings
the financial means whereby one lives	any of several nutritive milklike liquids

sustenance (verb)	milk (verb)
	take milk from female mammals
	add milk to
	exploit as much as possible