\Sharp"en\, v. t. [imp. & p. p. {Sarpened}; p. pr. & vb.
n. {Sharpening}.] [See {Sharp}, a.]
To make sharp. Specifically:
(a) To give a keen edge or fine point to; to make sharper;
    as, to sharpen an ax, or the teeth of a saw.
(b) To render more quick or acute in perception; to make more
    ready or ingenious.
          The air . . . sharpened his visual ray To objects
          distant far.                         --Milton.
          He that wrestles with us strengthens our nerves and
          sharpens our skill.                  --Burke.
(c) To make more eager; as, to sharpen men's desires.
          Epicurean cooks Sharpen with cloyless sauce his
          appetite.                            --Shak.
(d) To make more pungent and intense; as, to sharpen a pain
    or disease.
(e) To make biting, sarcastic, or severe. ``Sharpen each
    word.'' --E. Smith.
(f) To render more shrill or piercing.
          Inclosures not only preserve sound, but increase
          and sharpen it.                      --Bacon.
(g) To make more tart or acid; to make sour; as, the rays of
    the sun sharpen vinegar.
(h) (Mus.) To raise, as a sound, by means of a sharp; to
    apply a sharp to.

\Sharp"en\, v. i.
To grow or become sharp.