Definition of "fail" [fail]

  • To prove deficient or lacking; perform ineffectively or inadequately: failed to fulfill their promises; failed in their attempt to reach the summit. (verb-intransitive)
  • To be unsuccessful: an experiment that failed. (verb-intransitive)
  • To receive an academic grade below the acceptable minimum. (verb-intransitive)
  • To prove insufficient in quantity or duration; give out: The water supply failed during the drought. (verb-intransitive)
  • To decline, as in strength or effectiveness: The light began to fail. (verb-intransitive)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Use "fail" in a sentence
  • "'You can't fail,' she said, '_I won't let you fail_!'"
  • "[Illustration: "And he," she said, "has still a chance if -- I fail you?"] "Of course -- if you _fail_ me.""
  • "We shall not fail -- if we stand firm, we _shall not fail_."