The Collaborative International Dictionary of English v.0.48:

Footstall \Foot"stall`\, n. [Cf. Pedestal.]
   1. The stirrup of a woman's saddle.
      [1913 Webster]

   2. (Arch.) The plinth or base of a pillar.
      [1913 Webster]

WordNet (r) 3.0 (2006):

footstall
    n 1: an architectural support or base (as for a column or
         statue) [syn: pedestal, plinth, footstall]