The Collaborative International Dictionary of English v.0.48:

Stile \Stile\, n. [See Style.]
   1. A pin set on the face of a dial, to cast a shadow; a
      style. See Style. --Moxon.
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   2. Mode of composition. See Style. [Obs.]
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            May I not write in such a stile as this? --Bunyan.
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The Collaborative International Dictionary of English v.0.48:

Stile \Stile\, n. [OE. stile, AS. stigel a step, a ladder, from
   st[imac]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.
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            There comes my master . . . over the stile, this
            way.                                  --Shak.
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            Over this stile in the way to Doubting Castle.
                                                  --Bunyan.
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   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.
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   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.
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   Hanging stile, Pulley stile. See under Hanging, and
      Pulley.
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WordNet (r) 3.0 (2006):

stile
    n 1: an upright that is a member in a door or window frame