The Collaborative International Dictionary of English v.0.48:

Tear \Tear\ (t[=e]r), n. [AS. te['a]r; akin to G. z[aum]rhe,
   OHG. zahar, OFries. & Icel. t[=a]r, Sw. t[*a]r, Dan. taare,
   Goth. tagr, OIr. d[=e]r, W. dagr, OW. dacr, L. lacrima,
   lacruma, for older dacruma, Gr. da`kry, da`kryon, da`kryma.
   [root]59. Cf. Lachrymose.]
   1. (Physiol.) A drop of the limpid, saline fluid secreted,
      normally in small amount, by the lachrymal gland, and
      diffused between the eye and the eyelids to moisten the
      parts and facilitate their motion. Ordinarily the
      secretion passes through the lachrymal duct into the nose,
      but when it is increased by emotion or other causes, it
      overflows the lids.
      [1913 Webster]

            And yet for thee ne wept she never a tear.
                                                  --Chaucer.
      [1913 Webster]

   2. Something in the form of a transparent drop of fluid
      matter; also, a solid, transparent, tear-shaped drop, as
      of some balsams or resins.
      [1913 Webster]

            Let Araby extol her happy coast,
            Her fragrant flowers, her trees with precious tears.
                                                  --Dryden.
      [1913 Webster]

   3. That which causes or accompanies tears; a lament; a dirge.
      [R.] "Some melodous tear." --Milton.
      [1913 Webster]

   4. (Glass Manuf.) A partially vitrified bit of clay in glass.
      [Webster 1913 Suppl.]

   Note: Tear is sometimes used in the formation of
         self-explaining compounds; as, tear-distilling,
         tear-drop, tear-filled, tear-stained, and the like.
         [1913 Webster]

   Tears of St. Lawrence, the Perseid shower of meteors, seen
      every year on or about the eve of St. Lawrence, August
      9th.

   Tears of wine, drops which form and roll down a glass above
      the surface of strong wine. The phenomenon is due to the
      evaporation of alcohol from the surface layer, which,
      becoming more watery, increases in surface tension and
      creeps up the sides until its weight causes it to break.
      [Webster 1913 Suppl.]