—adj. 1. moving or able to move, operate, function, or take effect quickly; quick; swift; rapid: a fast horse; a fast pain reliever; a fast thinker. 2. done in comparatively little time; taking a comparatively short time: a fast race; fast work. 3. (of time)
a. indicating a time in advance of the correct time, as of a clock.
b. noting or according to daylight-saving time.
4. adapted to, allowing, productive of, or imparting rapid movement: a hull with fast lines; one of the fastest pitchers in baseball. 5. characterized by unrestrained conduct or lack of moral conventions, esp. in sexual relations; wanton; loose: Some young people in that era were considered fast, if not downright promiscuous. 6. characterized by hectic activity: leading a fast life. 7. resistant: acid-fast. 8. firmly fixed in place; not easily moved; securely attached.
9. held or caught firmly, so as to be unable to escape or be extricated: an animal fast in a trap. 10. firmly tied, as a knot.
11. closed and made secure, as a door, gate, or shutter.
12. such as to hold securely: to lay fast hold on a thing. 13. firm in adherence; loyal; devoted: fast friends. 14. permanent, lasting, or unchangeable: a fast color; a hard and fast rule. 15. Informal. a. (of money, profits, etc.) made quickly or easily and sometimes deviously: He earned some fast change helping the woman with her luggage. b. cleverly quick and manipulative in making money: a fast operator when it comes to closing a business deal. 16. Photog. a. (of a lens) able to transmit a relatively large amount of light in a relatively short time.
b. (of a film) requiring a relatively short exposure time to attain a given density.
17. Horse Racing. a. (of a track condition) completely dry.
b. (of a track surface) very hard.
18. pull a fast one,Informal.to play an unfair trick; practice deceit: He tried to pull a fast one on us by switching the cards.
—adv. 1. quickly, swiftly, or rapidly.
2. in quick succession: Events followed fast upon one another to the crisis. 3. tightly; firmly: to hold fast. 4. soundly: fast asleep. 5. in a wild or dissipated way.
6. ahead of the correct or announced time.
7. Archaic.close; near: fast by. 8. play fast and loose. See play (def. 76).
—n. a fastening for a door, window, or the like.
Pronunciation: (fast, fäst),[key] —v.i. 1. to abstain from all food.
2. to eat only sparingly or of certain kinds of food, esp. as a religious observance.
—v.t. to cause to abstain entirely from or limit food; put on a fast: to fast a patient for a day before surgery.
—n. 1. an abstinence from food, or a limiting of one's food, esp. when voluntary and as a religious observance; fasting.
2. a day or period of fasting.
Pronunciation: (fast, fäst),[key] —n. a chain or rope for mooring a vessel.