- The edible root of a plant, Wasabia japonica, which only grows in Japan. The skinned, pale green root has a fierce flavour rather like horseradish. It is grated and served like this or made into a paste for use with sashimi or in sushi. It can also be dried to a pale brown powder.
- noun a strong-tasting green powder or paste from a plant root used as a condiment in Japanese cooking