Frequency: The word is one of the 1500 most common words in English.
1.
You refer to an activity or situation as fun if you think it is pleasant and enjoyable and it causes you to feel happy.
It was such a success and we had so much fun doing it...
It could be fun to watch them...
You still have time to join in the fun.
N-UNCOUNT
2.
If you say that someone is fun, you mean that you enjoy being with them because they say and do interesting or amusing things.
Liz was wonderful fun to be with.
N-UNCOUNT [approval]
3.
If you describe something as a fun thing, you mean that you think it is enjoyable. If you describe someone as a fun person, you mean that you enjoy being with them. (INFORMAL)
It was a fun evening...
What a fun person he is!
= entertaining
ADJ: ADJ n
4.
Someone who is a figure of fun is considered ridiculous, so that people laugh at them or make jokes about them.
PHRASE: figure inflects, v-link PHR
5.
If you do something for fun or for the fun of it, you do it in order to enjoy yourself rather than because it is important or necessary.
I took my M. A. just for fun really...
He had just come for the fun of it.
PHRASE: PHR after v
6.
If you do something in fun, you do it as a joke or for amusement, without intending to cause any harm.
Don't say such things, even in fun.
PHRASE: PHR after v, v-link PHR
7.
If you make fun of someone or something or poke fun at them, you laugh at them, tease them, or make jokes about them in a way that causes them to seem ridiculous.
Don't make fun of me...
She poked fun at people's shortcomings.
PHRASE: V inflects, PHR n