Meaning of fast in English
His legs are fast. ― He is a fast runner. ― He runs fast.
1. quickly
There are many ways to lose a lot of weight fast.
2. firmly
3. deeply
She is fast asleep.
fast2
1. the practice or period of fasting
1. eat a little or no food for a period of time
He fasted[abstained from food] for five days.