1 able to move or act at great speed 快的；迅速的: a fast car/worker/runner/reader 开得快的汽车；干活快的工人；跑得快的选手；阅读速度快的人 ☞ Look at the note at quick. 参看quick的注释。

2 (used about a clock or watch) showing a time that is later than the real time （指钟表）走快了的: The clock is five minutes fast. 那钟快了五分钟。 [OPP] slow 反义词为slow

3 (used about camera film) very sensitive to light, and therefore good for taking photographs in poor light or of things that are moving quickly （指胶卷）感光快的（可在光线差的情况下拍摄或拍快速移动的物体）

4 (not before a noun 只用于名词前) firmly fixed 紧紧固定；牢固；稳固: He made the boat fast (= he tied it to something) before he got out. 他把船拴紧了才上岸。Do you think the colour in this T-shirt is fast (= will not come out when washed)? 你认为这件T恤不会褪色？