1. a very valuable and highly esteemed underground fungus, which until recently, couldn't be cultivated, only aged, often found with the use of pigs. (China and some other countries are now cultivating truffles on a small scale.) The black truffle, Tuber melanosporum, was known by both the Greeks and the Romans, who endorsed its medicinal and especially aphrodisiac attributes. Truffles were an Egyptian favorite, eaten with goose fat. But in the Middle Ages, they were thought to be manifestations of the devil. Louis XIV, however, subscribed to the earlier theory, and from his reign onward, truffles were enthusiastically consumed by all those wealthy enough to afford them. Since the 17th century, pigs have been used to find truffles, but they developed a taste for them, so truffle pigs are now muzzled. It's also become efficient to use specially trained dogs. In Italy, these dogs can cost more than $10,000. A trained eye can spot a small hole leading under the tree, and by delicately foraging inside with a small stick, one can find a truffle. The best black truffles are said to come from the French regions of Perigord and Provence, and Piedmont, in Italy, is famous for its more subtly scented white truffle, Tuber magnatum. There are more than 70 varieties of truffles, and China now exports some lesser-quality truffles at a very low price. 2. a small chocolate, often with a soft center, so named because a signature variety had an irregular round shape and was dredged in cocoa, which mimicked the appearance of the fungus.