detention vs custody

detention and custody both are nouns.

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

As nouns, detention and custody are synonyms defined as:

detention and custody: a state of being confined (usually for a short time)

Other synonyms of detention include detainment, hold.

detention (noun)	custody (noun)
a punishment in which a student must stay at school after others have gone home	holding by the police
a state of being confined (usually for a short time)	(with `in') guardianship over; in divorce cases it is the right to house and care for and discipline a child
	a state of being confined (usually for a short time)