adjective

 

quick moving, happening, or doing something quickly

fast cars

 

time If a clock or watch is fast, it shows a time that is later than the correct time.

My watch is five minutes fast.

 

adverb

 

quickly moving or happening quickly

We ran as fast as we could.

 

firmly in a firm or tight way

He tried to get away, but she held him fast.

 

verb

 

to eat nothing, or much less than you usually eat for a period of time