Verb

(mitigat)

To reduce, lessen, or decrease.

* 1795 —

Measures are pursuing to prevent or mitigate the usual consequences of such outrages, and with the hope of their succeeding at least to avert general hostility.

* 1813 —

But in yielding to it the retaliation has been mitigated as much as possible, both in its extent and in its character...

* 1896 —

Then they tell us that vaccination will mitigate the disease that it will make it milder.

* 1901 — , ch 7

Then I discovered the brilliance of the landscape around was mitigated by blue spectacles.

* 1920 —

The plague had not been kind to him, yet had left him this small furry thing to mitigate his sorrow; and when one is very young, one can find great relief in the lively antics of a black kitten.

To downplay.

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.