fun
Enjoyable activity or feeling that makes you happy and playful.
Fun is the light, energetic pleasure that makes you want to smile, laugh, or keep doing whatever you're doing. When something is fun, time seems to fly by because you're fully absorbed in enjoying yourself. A fun game keeps you engaged and entertained. A fun friend makes you laugh and turns ordinary moments into adventures.
Fun comes in countless varieties. Building with blocks might be fun for one person, while reading mysteries is fun for another. Some people find fun in active, noisy activities like tag or soccer, while others find it in quiet pursuits like drawing or solving puzzles. The activity itself matters less than how it makes you feel: alert, interested, and genuinely happy to be doing it.
Notice that fun isn't the same as important or meaningful, though activities can certainly be both. Practicing piano scales might not feel fun while you're doing it, even if you love performing later. When something is just for fun, it means you're doing it purely for enjoyment, not because you have to or because you'll get something else from it.
The phrase make fun of means something completely different: mocking or teasing someone unkindly, which isn't fun at all for the person being targeted.