In the Times today, Ross Clark writes (apropros of a branch of Sainsbury’s removing kosher products from their shelves while “Free Gaza” protests were going on outside): “equating kosher food and Israeli action in Gaza belies casual anti-semitism”. If I have understood him correctly, then I think Ross Clark is right. But he didn’t mean belies. He meant reveals.
I have seen this mistake a lot. The word belie means “give the lie to” – an action or statement which is in contradiction to the reality belies it; thus, one might say, “His apparent friendliness belied his deep antipathy towards her”. In fact it means something more like conceal than reveal. Odd that it is so often used to mean its opposite.