sponsor (n.)
1650s, from Late Latin sponsor "sponsor in baptism," in Latin "a surety, guarantee, bondsman," from sponsus, past participle of spondere "give assurance, promise solemnly" (see spondee). Sense of "person who pays for a radio (or, after 1947, TV) program" is first recorded 1931.
sponsor (v.)
1884, "to favor or support," from sponsor (n.). Commercial broadcasting sense is from 1931. Related: Sponsored; sponsoring.