Formal:
* Absurde: This is the most common and neutral translation.
* Ridicule: This is the direct translation, but it's not as commonly used in everyday speech.
Informal:
* Débile: This is a more informal and colloquial word, similar to "silly" or "stupid."
* N'importe quoi: This literally means "anything," but it's used to express disbelief or to say something is ridiculous.
* C'est du n'importe quoi: This means "It's anything," and it's a more emphatic way to say something is ridiculous.
Other options:
* Dingue: This means "crazy" or "insane" and can be used to describe something as ridiculous.
* Incroyable: This means "incredible" but can be used sarcastically to express disbelief or ridicule.
The best way to choose the right word depends on the situation and your audience.