Source : Webster's Revised Unabridged Dictionary (1913)

Voidable \Void"a*ble\, a.
   1. Capable of being voided, or evacuated.

   2. (Law) Capable of being avoided, or of being adjudged void,
      invalid, and of no force; capable of being either avoided
      or confirmed.

            If the metropolitan . . . grants letters of
            administration, such administration is not, but
            voidable by sentence.                 --Ayliffe.

   Note: A voidable contract may be ratified and confirmed; to
         render it null and of no effect, it must be avoided; a
         void contract can not be ratified.

Source : WordNet®

voidable
     adj : capable of being rescinded or voided; "the judgment was
           rescindable"; "voidable contracts" [syn: {rescindable}]