a brown seaweed, Undaria pinnatifida, of coastal Japan, Korea, etc., growing in coarse, stringy clumps and usually dried for use in Asian soups, salads, and side dishes.
wa·ka·me (wä-kä'mě) n. A brown seaweed (Undaria pinnatifida) native to the coasts of China, Japan, and Korea, having a short stipe and pinnately divided blades, extensively used in Asian cooking.