a. - To make sharp.
a. - To give a keen edge or fine point to; to make sharper; as, to sharpen an ax, or the teeth of a saw.
a. - To render more quick or acute in perception; to make more ready or ingenious.
a. - To make more eager; as, to sharpen men's desires.
a. - To make more pungent and intense; as, to sharpen a pain or disease.
a. - To make biting, sarcastic, or severe.
a. - To render more shrill or piercing.
a. - To make more tart or acid; to make sour; as, the rays of the sun sharpen vinegar.
a. - To raise, as a sound, by means of a sharp; to apply a sharp to.
v. i. - To grow or become sharp.