Source : Webster's Revised Unabridged Dictionary (1913)

Frailty \Frail"ty\, n.; pl. {Frailties}. [OE. frelete, freilte,
   OF. frailet['e], fr. L. fragilitas. See {Frail}, a., and cf.
   {Fragility}.]
   1. The condition quality of being frail, physically,
      mentally, or morally, frailness; infirmity; weakness of
      resolution; liableness to be deceived or seduced.

            God knows our frailty, [and] pities our weakness.
                                                  --Locke.

   2. A fault proceeding from weakness; foible; sin of
      infirmity.

   Syn: Frailness; fragility; imperfection; failing.

Source : WordNet®

frailty
     n 1: the state of being weak in health or body (especially from
          old age) [syn: {infirmity}, {debility}, {feebleness}, {frailness}]
     2: moral weakness [syn: {vice}]