Source : Webster's Revised Unabridged Dictionary (1913)

Unmovable \Un*mov"a*ble\, a.
   Immovable. ``Steadfast, unmovable.'' --1 Cor. xv. 58. Locke.

Source : WordNet®

unmovable
     adj : not able or intended to be moved; "the immovable hills"
           [syn: {immovable}, {immoveable}, {stabile}]