General:
* rápido/rápida (masculine/feminine) - This is the most common and general translation for "fast."
* velo(z) (masculine/feminine) - While less common, it can be used for "fast" as well.
Specific contexts:
* de pressa - This phrase means "in a hurry" or "in a rush."
* apressado/apressada (masculine/feminine) - This means "hurried" or "rushed."
* ligeiro/ligeira (masculine/feminine) - This means "light" or "quick" and can be used to describe something that moves or happens quickly.
The best translation depends on the specific situation and the nuance you want to convey.