Source : Webster's Revised Unabridged Dictionary (1913)

Foible \Foi"ble\, a. [OF. foible. See {Feeble}.]
   Weak; feeble. [Obs.] --Lord Herbert.

Foible \Foi"ble\, n.
   1. A moral weakness; a failing; a weak point; a frailty.

            A disposition radically noble and generous, clouded
            and overshadowed by superficial foibles. --De
                                                  Quincey.

   2. The half of a sword blade or foil blade nearest the point;
      -- opposed to forte. [Written also {faible}.]

   Syn: Fault; imperfection; failing; weakness; infirmity;
        frailty; defect. See {Fault}.

Source : WordNet®

foible
     n 1: a behavioral attribute that is distinctive and peculiar to
          an individual [syn: {idiosyncrasy}, {mannerism}]
     2: the weaker part of a sword's blade from the forte to the tip