Veneer is a thin layer of attractive wood (or other material) glued on top of cheaper wood, to enhance the overall appearance. Usually the term is used figuratively, meaning anything that covers the real nature of something.
Nelson Mandela wants to use the rugby World Cup, for white South Africans the absolute pinnacle of sport, to prevent the veneer of social unity from being rent asunder. (The Economist)
The music is broken up into obvious, clean-cut solos and Mr. Kuhn, for the most part, sticks to straight-ahead, swinging 4/4 time. But under that veneer, Mr. Kuhn is always thinking, and a close listener will hear a world filled with humor and slyness. (NY Times)