Source : Webster's Revised Unabridged Dictionary (1913)

Flexible \Flex"i*ble\, a. [L. flexibilis: cf. F. flexible.]
   1. Capable of being flexed or bent; admitting of being
      turned, bowed, or twisted, without breaking; pliable;
      yielding to pressure; not stiff or brittle.

            When the splitting wind Makes flexible the knees of
            knotted oaks.                         --Shak.

   2. Willing or ready to yield to the influence of others; not
      invincibly rigid or obstinate; tractable; manageable;
      ductile; easy and compliant; wavering.

            Phocion was a man of great severity, and no ways
            flexible to the will of the people.   --Bacon.

            Women are soft, mild, pitiful, and flexible. --Shak.

   3. Capable or being adapted or molded; plastic,; as, a
      flexible language.

            This was a principle more flexible to their purpose.
                                                  --Rogers.

   Syn: Pliant; pliable; supple; tractable; manageable; ductile;
        obsequious; inconstant; wavering. -- {Flex"i*ble*ness},
        n. -- {Flex"i*bly}, adv.

Source : WordNet®

flexible
     adj 1: extended meanings; capable of change; "a flexible
            character"; "flexible schedules" [ant: {inflexible}]
     2: able to flex; able to bend easily; "slim flexible birches"
        [syn: {flexile}] [ant: {inflexible}]
     3: able to adjust readily to different conditions; "an
        adaptable person"; "a flexible personality"; "an elastic
        clause in a contract" [syn: {elastic}, {pliable}, {pliant}]
     4: bending and snapping back readily without breaking
     5: making or willing to make concessions; "loneliness tore
        through him...whenever he thought of...even the
        compromising Louis du Tillet" [syn: {compromising}, {conciliatory}]
        [ant: {uncompromising}]