To make sharp. Specifically:
To give a keen edge or fine point to; to make sharper; as, to sharpen an ax, or the teeth of a saw.
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)
To make more eager; as, to sharpen men's desires. Epicurean cooks Sharpen with cloyless sauce his appetite. (Shak)
To make more pungent and intense; as, to sharpen a pain or disease.
To make biting, sarcastic, or severe. Sharpen each word. .
To render more shrill or piercing. Inclosures not only preserve sound, but increase and sharpen it. (bacon)
To make more tart or acid; to make sour; as, the rays of the sun sharpen vinegar.
To raise, as a sound, by means of a sharp; to apply a sharp to.
Origin: See Sharp.