Source : Webster's Revised Unabridged Dictionary (1913)

Stile \Stile\, n. [See {Style}.]
   1. A pin set on the face of a dial, to cast a shadow; a
      style. See {Style}. --Moxon.

   2. Mode of composition. See {Style}. [Obs.]

            May I not write in such a stile as this? --Bunyan.

Stile \Stile\, n. [OE. stile, AS. stigel a step, a ladder, from
   st[=i]gan to ascend; akin to OHG. stigila a stile. [root]164.
   See {Sty}, v. i., and cf. {Stair}.]
   1. A step, or set of steps, for ascending and descending, in
      passing a fence or wall.

            There comes my master . . . over the stile, this
            way.                                  --Shak.

            Over this stile in the way to Doubting Castle.
                                                  --Bunyan.

   2. (Arch.) One of the upright pieces in a frame; one of the
      primary members of a frame, into which the secondary
      members are mortised.

   Note: In an ordinary door the principal upright pieces are
         called stiles, the subordinate upright pieces mullions,
         and the crosspieces rails. In wainscoting the principal
         pieces are sometimes called stiles, even when
         horizontal.

   {Hanging stile}, {Pulley stile}. See under {Hanging}, and
      {Pulley}.

Source : WordNet®

stile
     n : an upright that is a member in a door or window frame