[fast, fahst]

verb (used without object)

to abstain from all food.
to eat only sparingly or of certain kinds of food, especially as a religious observance.

verb (used with object)

to cause to abstain entirely from or limit food; put on a fast: to fast a patient for a day before surgery.


an abstinence from food, or a limiting of one's food, especially when voluntary and as a religious observance; fasting.
a day or period of fasting.

Nearby words

  1. fashoda incident,
  2. fasnacht,
  3. fassa,
  4. fassbinder,
  5. fassbinder, rainer werner,
  6. fast and furious,
  7. fast and loose,
  8. fast break,
  9. fast buck,
  10. fast casual

Origin of fast

before 1000; Middle English fasten, Old English fæstan; cognate with German fasten, Gothic fastan, Old Norse fasta

Related formsun·fast·ing, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fasting

British Dictionary definitions for fasting




acting or moving or capable of acting or moving quickly; swift
accomplished in or lasting a short timefast work; a fast visit
(prenominal) adapted to or facilitating rapid movementthe fast lane of a motorway
requiring rapidity of action or movementa fast sport
(of a clock, etc) indicating a time in advance of the correct time
given to an active dissipated life
of or characteristic of such activitya fast life
not easily moved; firmly fixed; secure
firmly fastened, secured, or shut
steadfast; constant (esp in the phrase fast friends)
sport (of a playing surface, running track, etc) conducive to rapid speed, as of a ball used on it or of competitors playing or racing on it
that will not fade or change colour readilya fast dye
  1. proof against fadingthe colour is fast to sunlight
  2. (in combination)washfast
  1. requiring a relatively short time of exposure to produce a given densitya fast film
  2. permitting a short exposure timea fast shutter
cricket (of a bowler) characteristically delivering the ball rapidly
informal glib or unreliable; deceptivea fast talker
archaic sound; deepa fast sleep
informal a deceptive or unscrupulous trick (esp in the phrase pull a fast one)
fast worker a person who achieves results quickly, esp in seductions


quickly; rapidly
soundly; deeplyfast asleep
firmly; tightly
in quick succession
in advance of the correct timemy watch is running fast
in a reckless or dissipated way
fast by or fast beside archaic close or hard by; very near
play fast and loose informal to behave in an insincere or unreliable manner


archery (said by the field captain to archers) stop shooting!

Word Origin for fast

Old English fæst strong, tight; related to Old High German festi firm, Old Norse fastr




(intr) to abstain from eating all or certain foods or meals, esp as a religious observance


  1. an act or period of fasting
  2. (as modifier)a fast day
Derived Formsfaster, noun

Word Origin for fast

Old English fæstan; related to Old High German fastēn to fast, Gothic fastan

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for fasting
Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with fasting


In addition to the idioms beginning with fast

  • fast and furious
  • fast and loose
  • fast buck
  • fast lane
  • fast track

also see:

  • get nowhere (fast)
  • hard and fast
  • pull a fast one
  • stand one's ground (fast)
  • thick and fast
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.