(esp. formerly) an institution for the maintenance and care of the mentally ill, orphans, or other persons requiring specialized assistance.

an inviolable refuge, as formerly for criminals and debtors; sanctuary

He sought asylum in the church.

International Law .

a refuge granted an alien by a sovereign state on its own territory.

a temporary refuge granted political offenders, esp. in a foreign embassy.

any secure retreat.

noun

cover , den , harbor , haven , hideaway , hideout , hole , ivory tower * , port , preserve , refuge , retreat , safe house , safety , sanctuary , security , shelter , institution , loony bin * , madhouse * , mental hospital , mental institution , sanatorium , hospice , hospital , covert , protection , harborage , bedlam