Source : Webster's Revised Unabridged Dictionary (1913)

Smile \Smile\, v. t.
   1. To express by a smile; as, to smile consent; to smile a
      welcome to visitors.

   2. To affect in a certain way with a smile. [R.]

            And sharply smile prevailing folly dead. --Young.

Smile \Smile\, n. [CF. Dan. smiil, Sw. smil. See {Smile}, v. i.]
   1. The act of smiling; a peculiar change or brightening of
      the face, which expresses pleasure, moderate joy, mirth,
      approbation, or kindness; -- opposed to {frown}.

            Sweet intercourse Of looks and smiles: for smiles
            from reason flow.                     --Milton.

   2. A somewhat similar expression of countenance, indicative
      of satisfaction combined with malevolent feelings, as
      contempt, scorn, etc; as, a scornful smile.

   3. Favor; countenance; propitiousness; as, the smiles of
      Providence. ``The smile of heaven.'' --Shak.

   4. Gay or joyous appearance; as, the smiles of spring.

            The brightness of their [the flowers'] smile was
            gone.                                 --Bryant.

Smile \Smile\ (sm[imac]l), v. i. [imp. & p. p. {Smiled}
   (sm[imac]ld); p. pr. & vb. n. {Smiling}.] [OE. smilen; akin
   to Dan. smile, Sw. smila, MHG. smielen, smieren, L. mirari to
   wonder at, Skr. smi to smile; and probably to E. smicker.
   [root]173. Cf. {Admire}, {Marvel}, {Smirk}.]
   1. To express amusement, pleasure, moderate joy, or love and
      kindness, by the features of the face; to laugh silently.

            He doth nothing but frown. . . . He hears merry
            tales and smiles not.                 --Shak.

            She smiled to see the doughty hero slain. --Pope.

            When last I saw thy young blue eyes, they smiled.
                                                  --Byron.

   2. To express slight contempt by a look implying sarcasm or
      pity; to sneer.

            'T was what I said to Craggs and Child, Who praised
            my modesty, and smiled.               --Pope.

   3. To look gay and joyous; to have an appearance suited to
      excite joy; as, smiling spring; smiling plenty.

            The desert smiled, And paradise was opened in the
            wild.                                 --Pope.

   4. To be propitious or favorable; to favor; to countenance;
      -- often with on; as, to smile on one's labors.

Source : WordNet®

smile
     n : a facial expression characterized by turning up the corners
         of the mouth; usually shows pleasure or amusement [syn: {smiling},
          {grin}, {grinning}]

smile
     v 1: change one's facial expression by spreading the lips, often
          to signal pleasure
     2: express with a smile; "She smiled her thanks"