noun
Refers to a facility that cares for and raises children, especially those without parents. Can also be used for a nursery school or childcare institution, though 保育園 is more common for standard daycare.
彼女は育児院でボランティアをしている。
She volunteers at an orphanage.
戦後、多くの孤児が育児院に預けられた。
After the war, many orphans were placed in orphanages.
孤児院 explicitly means 'orphanage' and is more direct, while 育児院 can have a broader sense including nursery functions.
Compound of 育児 (childcare) + 院 (institution). The term is straightforward and modern, with no obscure historical derivation.