fun

Etymology

From 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”). Compare also Norwegian fomme, fume (“a fool”). More at fon, fond. As a noun, fun is recorded from 1700, with a meaning “a cheat, trick, hoax”, from a verb fun meaning “to cheat, trick” (1680s). The meaning “diversion, amusement” dates to the 1720s. The older meaning is preserved in the phrase to make fun of (1737) and in usage of the adjective funny. The use of fun as adjective is newest and is due to reanalysis of the noun; this was incipient in the mid-19th century. Alternative etymology connected Middle English fonne with Old Frisian fonna, fone, fomne, variant forms of fāmne, fēmne (“young woman, virgin”), from Proto-West Germanic *faimnijā, from Proto-Germanic *faimnijǭ (“maiden”), from Proto-Indo-European *peymen- (“girl”), *poymen- (“breast milk”). If so, then cognate with Old English fǣmne (“maid, virgin, damsel, bride”), West Frisian famke (“girl”), Saterland Frisian fone, fon (“woman, maid, servant," also "weakling, simpleton”).

noun

1. Amusement, enjoyment or pleasure.
   Grafting your boss's face onto the hind end of a donkey is fun, but serious fun is when you create the impossible and it looks real. 2000, Robert Stanley, The Complete Idiot's Guide to Adobe Photoshop 6, Alpha Books, page 377
2. Playful, often noisy, activity.

adj

1. (informal) Enjoyable or amusing.
   We had a fun time at the party.
   He is such a fun person to be with.
   He's the liberated character that everyone wants to be, so he was very fun to play 2016 January 11, Tom Bateman, quoted in Nigel Hunt, "Jekyll and Hyde, TV revamp of Robert Louis Stevenson classic, debuts on CBC-TV" CBC News, Canada
2. (informal) Whimsical or flamboyant.
   This year's fashion style is much more fun than recent seasons.

verb

1. (colloquial) To tease, kid, poke fun at, make fun of.
   Hey, don't get bent out of shape over it; I was just funning you.