-athon

After a vowel -thon.

An event long in duration, usually for fund-raising purposes.

The last part of marathon, from Marathōn in Greece, the scene of a victory over the Persians in 490 BC.

From the 1930s onwards, the ending of marathon was borrowed, originally in the US, to form words relating to some charitable activity. The first examples were walkathon, a long-distance walk organized as a fund-raising event, and radiothon, a prolonged radio broadcast by a person or group, similarly to raise money. Many examples have been created since, of which telethon, a long television programme to raise money for charity, has gone furthest towards general acceptance. Others are operathon, a marathon performance of opera; preachathon, an extended sermon; and swimathon, a sponsored swimming event. Some examples are facetious terms indicating an unreasonably extended happening, such as boreathon, an interminable occasion; plugathon, an extended advertisement for a product or person; and excuseathon, an over-extended apology for some mishap.