Informal and playful:
* "Bouseux": This is a playful term for someone who is clumsy or silly, often associated with rural or unsophisticated people.
* "Niais": This means "silly" or "foolish" and can be used to describe someone who is naive or easily fooled.
* "Glandou": This is a slang term for a "slacker" or "lazy person," but it can also be used playfully to describe someone who is goofy or awkward.
More critical and negative:
* "Imbécile": This means "imbecile" or "stupid" and is a more insulting term than the others.
* "Gentil": This word literally means "kind" or "gentle," but it can also be used sarcastically to describe someone who is foolish or naive.
* "Crétin": This means "cretin" and is a very offensive term used to describe someone who is mentally disabled. It should be used with extreme caution.
The best word to use will depend on the context and the tone you want to convey. It's always a good idea to be aware of the potential offense of certain terms and to consider your audience when choosing words.