Source : Webster's Revised Unabridged Dictionary (1913)

Inflexible \In*flex"i*ble\, a. [L. inflexiblis: cf. F.
   inflexible. See {In-} not, and {Flexible}.]
   1. Not capable of being bent; stiff; rigid; firm; unyielding.

   2. Firm in will or purpose; not to be turned, changed, or
      altered; resolute; determined; unyieding; inexorable;
      stubborn.

            ``Inflexibleas steel.''               --Miltom.

            Amanof upright and inflexibletemper . . . can
            overcome all private fear.            --Addison.

   3. Incapable of change; unalterable; immutable.

            The nature of things is inflexible.   --I. Watts.

   Syn: -- Unbending; unyielding; rigid; inexorable;
        pertinacious; obstinate; stubborn; unrelenting.

Source : WordNet®

inflexible
     adj 1: extended meanings; incapable of change; "a man of inflexible
            purpose" [ant: {flexible}]
     2: not making concessions; "took an uncompromising stance in
        the peace talks"; "uncompromising honesty" [syn: {uncompromising}]
        [ant: {compromising}]
     3: literal meanings; "an inflexible iron bar"; "an inflexible
        knife blade" [ant: {flexible}]
     4: incapable of adapting or changing to meet circumstances; "a
        rigid disciplinarian"; "an inflexible law"; "an unbending
        will to dominate" [syn: {rigid}, {unbending}]