burnish

磨く、研ぐ、光らす、茶色にする

(verb-transitive) To make smooth or glossy by or as if by rubbing; polish.
(verb-transitive) To rub with a tool that serves especially to smooth or polish.
(noun) A smooth glossy finish or appearance; luster.

This past week, Limbaugh insisted that the Obama White House would use the catastrophe in Haiti to "burnish" the president's standing and credibility "with the black community, in the both light-skinned and dark-skinned black community, in this country."