The Collaborative International Dictionary of English v.0.48:

Socle \So"cle\, n. [F., fr. L. socculus, dim. of soccus. See
   Sock a covering for the foot. Cf. Zocco.] (Arch.)
   (a) A plain block or plinth forming a low pedestal; any base;
       especially, the base of a statue, column, or the like.
       See Plinth.
   (b) A plain face or plinth at the lower part of a wall.
       --Oxf. Gloss.
       [1913 Webster]

WordNet (r) 3.0 (2006):

socle
    n 1: a plain plinth that supports a wall