The Collaborative International Dictionary of English v.0.48:

broadcasting \broad"cast`ing\ n.
   the medium that disseminates via telecommunications; radio
   and television.

   Syn: broadcast media.
        [WordNet 1.5]

   2. taking part in a radio or tv program.
      [WordNet 1.5]

WordNet (r) 3.0 (2006):

broadcasting
    n 1: a medium that disseminates via telecommunications [syn:
         broadcast medium, broadcasting]
    2: taking part in a radio or tv program

Moby Thesaurus II by Grady Ward, 1.0:

68 Moby Thesaurus words for "broadcasting":
   FCC, FM broadcasting, Federal Communications Commission, airing,
   attenuation, bandying, book, broadcast, bruiting, bruiting about,
   circulation, circumfusion, diffraction, diffusion, dilution,
   dispensation, dispersal, dispersion, display, dissemination,
   dissipation, distribution, divergence, evaporation, evulgation,
   expansion, fade-out, fragmentation, insemination, issuance, issue,
   mixing, peppering, periodical, planting, printing, promulgation,
   propagation, publication, publishing, radiation, radiobroadcasting,
   reforestation, resetting, retimbering, scattering, scatterment,
   seeding, semination, setting, shotgun pattern, sowing, spattering,
   splay, spread, spreading, spreading abroad, sprinkling,
   standard broadcasting, strewing, telecasting, tone control,
   transmission, transplantation, ventilation, vestigial transmission,
   volatilization, volume control