moving or capable of moving at high speed

a fast and powerful car

(of a clock or watch) showing a time ahead of the correct time

I keep my watch fifteen minutes fast

firmly fixed or attached

he made a rope fast to each corner

(of a film) needing only a short exposure

a 35-mm colour film which is ten times faster than Kodacolor II

(of a dye) not fading in light or when washed

the dyes are boiled with the yarn to produce a fast colour

engaging in or involving activities characterized by excitement, extravagance, and risk-taking

the fast life she led in London

(of a person) prone to act in an unacceptably familiar way

Mammy said, ‘Stop asking questions, you too damn farse.’

at high speed

he was driving too fast

so as to be hard to move; securely

the ship was held fast by the anchor chain

so as to be hard to wake

they were too fast asleep to reply

abstain from all or some kinds of food or drink, especially as a religious observance

the ministry instructed people to fast

an act or period of fasting

a five-day fast