When your friend makes you laugh, you can say she/he is funny. We use funny who makes you laugh. However, fun means an experience or activity that is very enjoyable and exciting. By the way, it can be better to use this dictionary http://www.ldoceonline.com/

A very noticeable difference, I think. Fun = enjoyable Funny = comical

They have different meanings. Fun = 好玩 (ie. good play) Funny = 滑稽 (ie. hilarious) In addition, 'fun' can be both a noun and an adjective. 'Funny' is an adjective, and its noun form is 'funniness'.