wasabi
A spice that has an extremely strong flavor. Its hotness is more akin to that of a hot mustard rather than the capsaicin in a chili pepper, producing vapors that stimulate the nasal passages more than the tongue.
Due to restraints on mass cultivation, especially outside of Japan, cheap "wasabi" is typically made from the faster and easier growing horseradish which they dye green. Horseradish is a relative of wasabi and is commonly referred to as "western wasabi" (西洋わさび) in Japan.