'broadcaster' ultimately comes from the verb 'broadcast.' 'Broadcast' is a compound of Old English 'brād' meaning 'broad' and the verb 'cast' (from Old Norse/Old English roots) meaning 'to throw; to scatter.' The agentive suffix '-er' (from Old English) was added to form 'broadcaster' meaning 'one who broadcasts.'

'broadcast' was first used in agriculture in the late 18th century to mean 'to scatter seed widely.' In the early 20th century the verb took on the sense 'to transmit radio signals to a wide audience.' The noun 'broadcaster' developed from this modern sense to denote people or organizations that transmit programs.

Initially, 'broadcast' meant 'to scatter seed widely,' but over time it evolved into 'to transmit audio/visual signals widely.' Consequently, 'broadcaster' came to mean 'an entity that transmits programs or content to the public.'