IPA: //ʌnˈfʌni//
KK: /ʌnˈfʌni/
Not amusing or entertaining; lacking humor.
The comedian's latest show was so unfunny that the audience barely laughed.
Unfunny → It is formed from "un-" (meaning not) and "funny" (from Old English *funnig*, meaning causing laughter or amusement). The word "unfunny" means not causing laughter or amusement.
Think of 'not' ('un-') and something that makes you laugh ('funny') — that's why unfunny means it doesn't make you laugh.