The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Shoring \Shor"ing\, n.
   1. The act of supporting or strengthening with a prop or
      shore.
      [1913 Webster]

   2. A system of props; props, collectively.
      [1913 Webster] Shorl

WordNet (r) 3.0 (2006):

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