confinement vs custody

confinement and custody both are nouns.

Word	Noun	Adjective	Verb	Adverb
confinement	Yes	No	No	No
custody	Yes	No	No	No

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

confinement (noun)	custody (noun)
the act of restraining of a person's liberty by confining them	holding by the police
the act of keeping something within specified bounds (by force if necessary)	(with `in') guardianship over; in divorce cases it is the right to house and care for and discipline a child
the state of being confined	a state of being confined (usually for a short time)
concluding state of pregnancy; from the onset of contractions to the birth of a child