To transmit (a radio or television program) for public or general use. To send out or communicate, especially by radio or television: The agency broadcast an urgent appeal for medical supplies. To make known over a wide area: broadcast rumors. See Synonyms at announce. To sow (seed) over a wide area, especially by hand. To transmit a radio or television program for public or general use. To be on the air: The station begins broadcasting at 6 A.M. To participate in a radio or television program. To send a transmission or signal; transmit. Transmission of a radio or television program or signal for public use. A radio or television program: watched the morning news broadcast. The duration of such a program. The act of scattering seed. Communicated by means of television or radio. Of or relating to television or radio communications: broadcast journalism; the print and broadcast media. Widely known. Scattered over a wide area. In a scattered manner.