Meaning

noun activities that are enjoyable or amusing

noun verbal wit or mockery (often at another's expense but not to be taken seriously)

noun violent and excited activity

originFrom Middle English fonne, fon (“foolish, simple, silly”) or fonnen (“make a fool of”), from Middle English fonne (“a fool, dupe”), probably of North Germanic origin, related to Swedish fånig (“foolish”), Swedish fåne (“a fool”), from Old Norse fáni (“vain person, swaggerer”), but of unknown ultimate origin. Perhaps related to or influenced by fjäll (“rock, cliff, mountain”). Compare also English…

Etymology from Wiktionary, CC BY-SA 3.0