1. Acting or moving or capable of acting or moving quickly
   "set a fast pace"; "a fast car"; "fast film"; "on the fast track in school"
    
2. (of surfaces) conducive to rapid speeds
   "a fast road"; "grass courts are faster than clay"
    
3. (music) at a rapid tempo
   "the band played a fast fox trot"
    
4. Hurried and brief
   "a fast visit";
   - flying, quick
    
5. (used of timepieces) indicating a time ahead of or later than the correct time
   "my watch is fast"
    
6. Securely fixed in place
   "The anchor held fast despite the storm";
   - firm, immobile
    
7. Unwavering in devotion to friend, vow or cause
   "fast friends";
   - firm, loyal, truehearted
    
8. (of a photographic lens or emulsion) causing a shortening of exposure time
   "a fast lens"
    
9. Resistant to destruction or fading
   "fast colours"
    
10. Unrestrained by convention or morality
    "fast women";
    - debauched, degenerate, degraded, dissipated, dissolute, libertine, profligate, riotous

1. Quickly or rapidly (often used as a combining form)
   "needs medical help fast"; "fast-running rivers"; "fast-breaking news"; "fast-opening (or fast-closing) shutters"; "how fast can he get here?"; "ran as fast as he could"
    
2. Firmly or closely
   "held fast to the rope"; "her foot was stuck fast";
   - tight, fastly [archaic]

1. Abstaining from food
   "fast is practised in many religions for spiritual purposes";
   - fasting

1. Abstain from certain foods, as for religious or medical reasons
   "Catholics sometimes fast during Lent"
    
2. Abstain from eating
   "Before the medical exam, you must fast"

Derived forms: fastest, fasted, fasting, fasts, faster

See also: accelerated, alacritous, allegretto, allegro, andantino, blistering, causative, double-quick, express, faithful, fast-breaking, fastness, fast-paced, fixed, fleet, high-speed, high-velocity, hot, hurried, hurrying, immediate, immoral, imperviable, impervious, instant, instantaneous, meteoric, nippy [Brit, informal], prestissimo, presto, prompt, quick, rapid, red-hot, scurrying, smart, smooth, speed, speedy, straightaway, sudden, superfast, swift, swiftness, vivace, windy, winged

Type of: abstain, abstinence, desist, refrain

Antonym: slow

Encyclopedia: Fast, Kelly