Noun:
1: fast, fasting abstaining from food
Verb:
1: fast abstain from certain foods, as for religious or medical reasons; "Catholics sometimes fast during Lent"
2: fast abstain from eating; "Before the medical exam, you must fast"
Adjective:
1: smart, hurrying, fast, winged, speedy, red-hot, accelerating, rapid, fast-breaking, quick, hot, speedy, straightaway, instantaneous, swift, high-velocity, instant, fast-paced, rapid, scurrying, speeding, quick, prompt, express, alacritous, high-speed, double-quick, immediate, blistering, fleet, accelerated, windy, meteoric acting or moving or capable of acting or moving quickly; "fast film"; "on the fast track in school"; "set a fast pace"; "a fast car"
2: fast (used of timepieces) indicating a time ahead of or later than the correct time; "my watch is fast"
3: presto, allegretto, allegro, prestissimo, andantino, fast, vivace at a rapid tempo; "the band played a fast fox trot"
4: smooth, fast (of surfaces) conducive to rapid speeds; "a fast road"; "grass courts are faster than clay"
5: locked, barred, bolted, secured, fastened, fast, latched firmly fastened or secured against opening; "windows and doors were all fast"; "a locked closet"; "left the house properly secured"
6: fast, imperviable, impervious resistant to destruction or fading; "fast colors"
7: degenerate, degraded, debauched, immoral, fast, dissolute, profligate, libertine, dissipated, riotous unrestrained by convention or morality; "Congreve draws a debauched aristocratic society"; "deplorably dissipated and degraded"; "riotous living"; "fast women"
8: flying, quick, fast, hurried hurried and brief; "paid a flying visit"; "took a flying glance at the book"; "a quick inspection"; "a fast visit"
9: firm, fast, fixed, immobile securely fixed in place; "the post was still firm after being hit by the car"
10: firm, loyal, truehearted, fast, faithful unwavering in devotion to friend or vow or cause; "a firm ally"; "loyal supporters"; "the true-hearted soldier...of Tippecanoe"- Campaign song for William Henry Harrison; "fast friends"
Adverb:
1: fast quickly or rapidly (often used as a combining form); "how fast can he get here?"; "ran as fast as he could"; "needs medical help fast"; "fast-running rivers"; "fast-breaking news"; "fast-opening (or fast-closing) shutters"
2: tight, fast firmly or tightly; "held fast to the rope"; "her foot was stuck fast"; "held tight"