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]