custom vs use

custom and use both are nouns.

Word	Noun	Adjective	Verb	Adverb
custom	Yes	Yes	No	No
use	Yes	No	Yes	No

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

custom: accepted or habitual practice
use: (psychology) an automatic pattern of behavior in reaction to a specific situation; may be inherited or acquired through frequent repetition

Other hyponyms of custom include Americanism, Anglicism, Britishism, consuetude, couvade, Germanism, habit, hijab, rite, ritual.

custom (noun)	use (noun)
accepted or habitual practice	the act of using
habitual patronage	(psychology) an automatic pattern of behavior in reaction to a specific situation; may be inherited or acquired through frequent repetition
a specific practice of long standing	exerting shrewd or devious influence especially for one's own advantage
money collected under a tariff	what something is used for
	a particular service
	(law) the exercise of the legal right to enjoy the benefits of owning property
	(economics) the utilization of economic goods to satisfy needs or in manufacturing

custom (adjective)	use (adjective)
made according to the specifications of an individual

custom (verb)	use (verb)
	put into service; make work or employ for a particular purpose or for its inherent or natural purpose
	take or consume (regularly or habitually)
	use up (resources or materials)
	habitually do something or be in a certain state or place (use only in the past tense)
	avail oneself to
	seek or achieve an end by using to one's advantage