Goofball

[Britney]

Someone who is silly or stupid. Also looks silly or stupid.

Opposite of a chill bro.

People generally laugh at them than with them.

[Rihanna]

A term of endearment between online friends, similar to buddy, bro, etc. Tends to be used when one friend does something silly or funny.
Used mainly in America by those unfamiliar with the derogative form of the word.

Also used: goof, goofball, goofy

[Cami]

A naive or stupid person.

[Monty]

A naive, silly, or stupid person.

[Mark Zuckerberg]

a person who is silly in a way that is funny, often intentionally: