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: swift, winged, hurrying, express, fast-breaking, fleet, instantaneous, fast, instant, rapid, speedy, double-quick, meteoric, high-velocity, alacritous, high-speed, blistering, prompt, quick, accelerated, hot, straightaway, quick, scurrying, rapid, windy, speeding, fast-paced, accelerating, immediate, speedy, red-hot, smart 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, prestissimo, fast, allegretto, vivace, allegro, andantino at a rapid tempo; "the band played a fast fox trot"
4: fast, smooth (of surfaces) conducive to rapid speeds; "a fast road"; "grass courts are faster than clay"
5: secured, barred, locked, fastened, fast, latched, bolted firmly fastened or secured against opening; "windows and doors were all fast"; "a locked closet"; "left the house properly secured"
6: impervious, fast, imperviable resistant to destruction or fading; "fast colors"
7: libertine, degenerate, immoral, riotous, fast, degraded, dissolute, debauched, profligate, dissipated unrestrained by convention or morality; "Congreve draws a debauched aristocratic society"; "deplorably dissipated and degraded"; "riotous living"; "fast women"
8: quick, flying, fast, hurried hurried and brief; "paid a flying visit"; "took a flying glance at the book"; "a quick inspection"; "a fast visit"
9: fast, fixed, immobile, firm securely fixed in place; "the post was still firm after being hit by the car"
10: faithful, firm, truehearted, fast, loyal 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: fast, tight firmly or tightly; "held fast to the rope"; "her foot was stuck fast"; "held tight"