Source : Webster's Revised Unabridged Dictionary (1913)

Sty \Sty\, n.; pl. {Sties}. [Written also {stigh}.] [AS. stigu,
   fr. st[=i]gan to rise; originally, probably, a place into
   which animals climbed or went up. [root]164. See {Sty}, v.
   i., and cf. {Steward}.]
   1. A pen or inclosure for swine.

   2. A place of bestial debauchery.

            To roll with pleasure in a sensual sty. --Milton.

Sty \Sty\, v. t. [imp. & p. p. {Stied}; p. pr. & vb. n.
   {Stying}.]
   To shut up in, or as in, a sty. --Shak.

Sty \Sty\, v. i. [OE. stien, sti?en, AS. st[=i]gan to rise; akin
   to D. stijgen, OS. & OHG. st[=i]gan, G. steigen, Icel.
   st[=i]ga, Sw. stiga, Dan. stige, Goth. steigan, L. vestigium
   footstep, Gr. ? to walk, to go, Skr. stigh to mount. Cf.
   {Distich}, {Stair} steps, {Stirrup}, {Sty} a boil, a pen for
   swine, {Vestige}.]
   To soar; to ascend; to mount. See {Stirrup}. [Obs.]

         With bolder wing shall dare aloft to sty, To the last
         praises of this Faery Queene.            --Spenser.

Sty \Sty\, n. [For older styan, styanye, understood as sty on
   eye, AS. st[=i]gend (sc. e['a]ge eye), properly, rising, or
   swelling (eye), p. p. of st[=i]gan to rise. See {Sty}, v. i.]
   (Med.)
   An inflamed swelling or boil on the edge of the eyelid.
   [Written also {stye}.]

Source : WordNet®

sty
     n 1: an infection of the sebaceous gland of the eyelid [syn: {stye},
           {hordeolum}, {eye infection}]
     2: a pen for swine [syn: {pigsty}, {pigpen}]
     [also: {stied}]