Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “fast”

fast

adjective
 
/fæst/
A1 quick: fast cars a fast swimmer → Opposite slow adj
If a clock or watch is fast, it shows a time that is later than the correct time: My watch is five minutes fast.
(Definition of fast adjective from the Websters Essential Mini Dictionary © Cambridge University Press)
Add Cambridge dictionaries to your browser to your website

More Essential American English definitions for “fast”

Definitions of “fast” in other dictionaries

Word of the Day

pint

a measure for liquid equal to about half a litre

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More