an on-the-air radio campaign, often lasting 24 hours or more, designed to raise money for a radio station, charity, the arts, etc., as from listeners phoning in and pledging specific donations, sometimes in exchange for gifts or premiums.

Compare telethon.

Origin of radiothon

1960–65, Americanism; radio + -thon Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for radiothon

telethon, bazaar, fundraiser, radiothon