Verb

(refin)

To reduce to a fine, unmixed, or pure state; to free from impurities; to free from dross or alloy; to separate from extraneous matter; to purify

* {{quote-magazine, date=2013-08-03, volume=408, issue=8847, magazine=(The Economist)

, title= Yesterday’s fuel , passage=The dawn of the oil age was fairly recent. Although the stuff was used to waterproof boats in the Middle East 6,000 years ago, extracting it in earnest began only in 1859 after an oil strike in Pennsylvania.

To purify from what is gross, coarse, vulgar, inelegant, low, and the like; to make elegant or excellent; to polish.

To become pure; to be cleared of feculent matter.

To improve in accuracy, delicacy, or excellence.

To affect nicety or subtlety in thought or language.

Verb

(en verb)

To change the form or structure of.

* Bible, Psalms lxxxix. 34

My covenant will I not break, nor alter the thing that is gone out of my lips.

* Shakespeare

No power in Venice can alter a decree.

* Alexander Pope

It gilds all objects, but it alters none.

To become different.

To tailor clothes to make them fit.

To castrate, neuter or spay (a dog or other animal).

(obsolete) To agitate; to affect mentally.

(Milton)