1 [more fast; most fast] a : moving or able to move quickly
▪ She's a very fast runner. ▪ a fast car ▪ a fast pitch ▪ maintaining a fast [=quick] pace ▪ blazingly/blindingly fast
b : happening quickly : taking a short amount of time
▪ a fast race ▪ We're off to a fast start. ▪ We're now experiencing a faster rate of inflation. ▪ I'd like to take a fast [=(more commonly) quick] look at my records.
c : operating quickly
▪ a fast computer
d : doing something or able to do something quickly
▪ a fast learner
e : allowing movement at a great speed
▪ a fast road ▪ We took the faster route. — see also fast lane, fast track 2 of a clock or watch : showing a time that is later than the correct time
▪ My watch is (ten minutes) fast. 3 photography : allowing photographs to be taken very quickly or when there is very little light
▪ fast film 4 informal a : tricky and unfair
▪ Be careful that he doesn't pull a fast one on you. [=that he doesn't trick or deceive you]
b : earned or gotten quickly and often in a dishonest way
▪ She's always looking to make a fast buck. ▪ fast money
c : quick and not safe to trust
▪ He gave us a lot of fast talk about how he was going to solve all our problems. — see also fast-talk 5 old-fashioned + humorous a : actively seeking excitement or pleasure : wild
▪ He runs with a pretty fast crowd. ▪ fast living
b of women : very willing to have sex
▪ a typical Western filled with outlaws, gamblers, and fast women 6 a : placed, tied, or attached in a way that is not easily moved
▪ Make the rope fast [=tie the rope securely] to the anchor.
b : closed tightly
▪ Make sure the door is fast. [=(more commonly) shut fast]
c : impossible to change — used in the phrase hard and fast ▪ There are no hard and fast rules to be followed when you plan a vacation. [=there are many ways to plan a vacation]
d : not likely to fade
▪ fast colors 7 : very loyal or faithful
▪ They became fast friends.