truffle

n. 1 edible rich-flavoured underground fungus. 2 sweet made of a chocolate mixture covered with cocoa etc. [probably dutch from french]

n. Any one of several kinds of roundish, subterranean fungi, usually of a blackish color. The French truffle (Tuber melanosporum) and the English truffle (T. aestivum) are much esteemed as articles of food.