fail / fāl/ • v. [intr.] 1. be unsuccessful in achieving one's goal: they failed to be ranked in the top ten. ∎  [tr.] be unsuccessful in (an examination, test, or interview): she failed her finals. ∎  [tr.] (of a person or a commodity) be unable to meet the standards set by (a test of quality or eligibility): the player has failed a drug test. ∎  [tr.] judge (someone, esp. in an examination) not to have passed.2. neglect to do something: failed to give adequate warnings. ∎  behave in a way contrary to hopes or expectations by not doing something: commuter chaos has again failed to materialize. ∎  (cannot fail to be/do something) used to express a strong belief that something must be the case: you cannot fail to be deeply impressed. ∎  (never fail to do something) used to indicate that something invariably happens: such comments never failed to annoy him. ∎  [tr.] desert or let down (someone): at the last moment her nerve failed her.3. break down; cease to work well: a truck whose brakes had failed. ∎  become weaker or of poorer quality; die away: the light began to fail. ∎  (esp. of a rain or a crop or supply) be lacking or insufficient when needed or expected. ∎  (of a business or a person) become bankrupt.• n. a grade that is not high enough to pass an examination or test.PHRASES: without fail absolutely predictably; with no exception: he writes every week without fail.ORIGIN: Middle English: from Old French faillir (verb), faille (noun), based on Latin fallere ‘deceive.’ An earlier sense of the noun was ‘failure to do or perform a duty,’ surviving in the phrase without fail.