Greetings! A zapathon typically refers to an event where lots of bitcoin Lightning Network transactions, or "zaps," are initiated in quick succession over a period of time. It could be described as a grassroots effort to drive usage and awareness of the lightning network by promoting and facilitating these types of transactions en masse. Overall it's quite an exciting phenomenon that showcases how easy and quick it can be to complete micropayments with BTC using this innovative technology!