Dictionary

Firmly or securely fixed in place; stable.

Example: That rope is dangerously loose. Make it fast!

Firm against attack; fortified by nature or art; impregnable; strong.

(of people) Steadfast, with unwavering feeling. (Now mostly in set phrases like fast friend(s).)

Moving with great speed, or capable of doing so; swift, rapid.

Example: I am going to buy a fast car.

In a firm or secure manner, securely; in such a way as not to be moved; safe, sound .

Example: Hold this rope as fast as you can.

(of sleeping) Deeply or soundly .

Example: He is fast asleep.

Immediately following in place or time; close, very near .

Example: Fast by the sturdy batsman the ball unheeded sped. / That ain't my style, said Casey. Strike one, the umpire said.

Quickly, with great speed; within a short time .

Example: Do it as fast as you can.

One who fasts, or voluntarily refrains from eating.