Source : Webster's Revised Unabridged Dictionary (1913)

Fault \Fault\, n. [OE. faut, faute, F. faute (cf. It., Sp., &
   Pg. falta), fr. a verb meaning to want, fail, freq., fr. L.
   fallere to deceive. See {Fail}, and cf. {Default}.]
   1. Defect; want; lack; default.

            One, it pleases me, for fault of a better, to call
            my friend.                            --Shak.

   2. Anything that fails, that is wanting, or that impairs
      excellence; a failing; a defect; a blemish.

            As patches set upon a little breach Discredit more
            in hiding of the fault.               --Shak.

   3. A moral failing; a defect or dereliction from duty; a
      deviation from propriety; an offense less serious than a
      crime.

   4. (Geol. & Mining)
      (a) A dislocation of the strata of the vein.
      (b) In coal seams, coal rendered worthless by impurities
          in the seam; as, slate fault, dirt fault, etc.
          --Raymond.

   5. (Hunting) A lost scent; act of losing the scent.

            Ceasing their clamorous cry till they have singled,
            With much ado, the cold fault cleary out. --Shak.

   6. (Tennis) Failure to serve the ball into the proper court.

   {At fault}, unable to find the scent and continue chase;
      hence, in trouble or embarrassment, and unable to proceed;
      puzzled; thrown off the track.

   {To find fault}, to find reason for blaming or complaining;
      to express dissatisfaction; to complain; -- followed by
      with before the thing complained of; but formerly by at.
      ``Matter to find fault at.'' --Robynson (More's Utopia).

   Syn: -- Error; blemish; defect; imperfection; weakness;
        blunder; failing; vice.

   Usage: {Fault}, {Failing}, {Defect}, {Foible}. A fault is
          positive, something morally wrong; a failing is
          negative, some weakness or falling short in a man's
          character, disposition, or habits; a defect is also
          negative, and as applied to character is the absence
          of anything which is necessary to its completeness or
          perfection; a foible is a less important weakness,
          which we overlook or smile at. A man may have many
          failings, and yet commit but few faults; or his faults
          and failings may be few, while his foibles are obvious
          to all. The faults of a friend are often palliated or
          explained away into mere defects, and the defects or
          foibles of an enemy exaggerated into faults. ``I have
          failings in common with every human being, besides my
          own peculiar faults; but of avarice I have generally
          held myself guiltless.'' --Fox. ``Presumption and
          self-applause are the foibles of mankind.''
          --Waterland.