confinement vs lying-in

confinement and lying-in both are nouns.

Word	Noun	Adjective	Verb	Adverb
confinement	Yes	No	No	No
lying-in	Yes	No	No	No

As nouns, confinement and lying-in are synonyms defined as:

confinement and lying-in: concluding state of pregnancy; from the onset of contractions to the birth of a child

Other synonyms of confinement include childbed, labor, labour, parturiency, travail.

confinement (noun)	lying-in (noun)
the act of restraining of a person's liberty by confining them	concluding state of pregnancy; from the onset of contractions to the birth of a child
the act of keeping something within specified bounds (by force if necessary)
the state of being confined
concluding state of pregnancy; from the onset of contractions to the birth of a child