Source : Webster's Revised Unabridged Dictionary (1913)

Shore \Shore\, v. t. [imp. & p. p. {Shored}; p. pr. & vb. n.
   {Shoring}.] [OE. schoren. See {Shore} a prop.]
   To support by a shore or shores; to prop; -- usually with up;
   as, to shore up a building.

Shoring \Shor"ing\, n.
   1. The act of supporting or strengthening with a prop or
      shore.

   2. A system of props; props, collectively.

Source : WordNet®

shoring
     n 1: a beam or timber that is propped against a structure to
          provide support [syn: {shore}]
     2: the act of propping up with shores [syn: {shoring up}, {propping
        up}]