(transitive) To purify; reduce to a fine, unmixed, or pure state; to free from impurities.

(intransitive) To become pure; to be cleared of impure matter.

(transitive) To purify of coarseness, vulgarity, inelegance, etc.; to polish.

(transitive, intransitive) To improve in accuracy, delicacy, or excellence.

(transitive) To make nice or subtle.