n. The act of protecting, or the state of being protected; defense; shelter or preservation from loss, injury, or any form of harm or evil: as, the protection of good laws; divine protection.n. That which protects or shields from harm; something that preserves from injury: as, camphor serves as a protection against moths.n. A writing that guarantees protection; a passport, safe-conduct, or other writing which secures the bearer from molestation; especially, a certificate of nationality issued by the customs authorities of the United States to seamen who are American citizens.n. In political economics, the theory, doctrine, or system of fostering or developing the industries of a country by means of imposts on products of the industries imported into that country; the discouragement of foreign competition with the industries of a country by imposing import duties, granting monopolies of commerce, etc.n. A writ issued to a person required to attend court as witness, juror, etc., to secure him from arrest for a certain time. Synonyms Guard, refuge, security.