0 a city in the US or Canada where illegal immigrants (= people who have moved to live in another country when they do not have the legal right to do this) are not prosecuted:
Houston is one of the better-known sanctuary cities for immigrants in the US.
She now opposes deporting illegal immigrants and cutting off funds to sanctuary cities.
She also voted in favor of legislation targeting and withholding federal funds from sanctuary cities.
He opposes amnesty and sanctuary cities.