truffle

Concise Oxford English Dictionary © 2008 Oxford University Press:
truffle/ˈtrʌfl/

▶noun

• 1 a strong-smelling underground fungus that resembles a rough-skinned potato, considered a culinary delicacy. [Family Tuberaceae.]

• 2 a soft sweet made of a chocolate mixture.

▶verb (usu. as noun truffling) hunt for truffles.

– origin C16: prob. via Du. from obs. Fr. truffle, perh. based on L. tubera, pl. of tuber ‘hump, swelling’.