Also found in: Thesaurus, Medical, Legal, Idioms, Encyclopedia, Wikipedia.

fast 1

adj. fast·er, fast·est
1. Acting, moving, or capable of acting or moving quickly; swift.
a. Accomplished in relatively little time: a fast visit.
b. Acquired quickly with little effort and sometimes unscrupulously: made a fast buck scalping tickets.
3. Quick to understand or learn; mentally agile: a class for the faster students.
4. Indicating a time somewhat ahead of the actual time: The clock is fast.
5. Allowing rapid movement or action: a fast running track.
6. Designed for or compatible with a short exposure time: fast film.
a. Disposed to dissipation; wild: ran with a fast crowd.
b. Flouting conventional moral standards; sexually promiscuous.
8. Resistant, as to destruction or fading: fast colors.
9. Firmly fixed or fastened: a fast grip.
10. Fixed firmly in place; secure: shutters that are fast against the rain.
11. Firm in loyalty: fast friends. See Synonyms at faithful.
12. Lasting; permanent: fast rules and regulations.
13. Deep; sound: in a fast sleep.
adv. faster, fastest
1. In a secure manner; tightly: hold fast.
2. To a sound degree; deeply: fast asleep.
3. In a rapid manner; quickly.
4. In quick succession: New ideas followed fast.
5. Ahead of the correct or expected time: a watch that runs fast.
6. In a dissipated, immoderate way: living fast.
7. Archaic Close by; near.

[Middle English, from Old English fæst, firm, fixed; see past- in Indo-European roots.]
Synonyms: fast1, rapid, swift, fleet2, speedy, quick, expeditious
These adjectives refer to something marked by great speed. Fast and rapid are often used interchangeably, though fast is more often applied to the person or thing in motion, and rapid to the activity or movement involved: a fast runner; rapid strides. Swift suggests smoothness and sureness of movement (a swift current), and fleet, lightness of movement (The cheetah is the fleetest of animals). Speedy refers to velocity (a speedy train) or to promptness or hurry (a speedy resolution to the problem). Quick most often applies to what takes little time or to what is prompt: a quick snack; your quick reaction. Expeditious suggests rapid efficiency: sent the package by the most expeditious means. See Also Synonyms at faithful.

fast 2

intr.v. fast·ed, fast·ing, fasts
1. To abstain from food.
2. To eat very little or abstain from certain foods, especially as a religious discipline.
1. The act or practice of abstaining from or eating very little food.
2. A period of such abstention or self-denial.

[Middle English fasten, from Old English fæstan; see past- in Indo-European roots.]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adv.1.fastest - most quicklyfastest - most quickly        
References in classic literature ?
I marched the Expedition down the steep and tedious mule-path and took up as good a position as I could upon the middle of the glacier--because Baedeker said the middle part travels the fastest.
The louder she screamed, the harder he whipped; and where the blood ran fastest, there he whipped longest.
All the time, our overfraught hearts are beating at a rate that would far outstrip the fastest gallop of the fastest horses ever foaled.
Marsh to send me the fastest trap he has, to drive me to the railway station.
As soon as the vessel discovered the galleys she went about with the object and in the hope of making her escape by her speed; but the attempt failed, for the chief galley was one of the fastest vessels afloat, and overhauled her so rapidly that they on board the brigantine saw clearly there was no possibility of escaping, and the rais therefore would have had them drop their oars and give themselves up so as not to provoke the captain in command of our galleys to anger.
He did not wait to question, but in an instant a guard was racing to the nearest dock and though the air was thin and almost gone at the rooftop they managed to launch the fastest one-man, air-scout machine that the skill of Barsoom had ever produced.
The Mongolia plied regularly between Brindisi and Bombay via the Suez Canal, and was one of the fastest steamers belonging to the company, always making more than ten knots an hour between Brindisi and Suez, and nine and a half between Suez and Bombay.
This oath was no longer a vain menace; for the fastest sailer in the Mediterranean would have been unable to overtake the little tartan, that with every stitch of canvas set was flying before the wind to Leghorn.
Achilles then went in pursuit of Polydorus son of Priam, whom his father had always forbidden to fight because he was the youngest of his sons, the one he loved best, and the fastest runner.
The main body of his pursuers were a considerable distance behind; several of the fastest runners were scattered in the advance; while a swift-footed warrior, armed with a spear, was not more than a hundred yards behind him.
The fastest flier of the Heliumetic Navy could not quickly enough have carried me far from this hideous creature.
The lamps were being lit, but the streets were dark enough and empty enough to let him walk his fastest, and to talk aloud as he walked.