kelp means: Use dried seaweed to make dashi stock. Sushi Rice uses Kombu (a dried, rolled kelp). It can be found in Japanese and Korean food markets, as well as health food shops. (in Cooking Dictionary)
What else does kelp mean?
One of many brown seaweeds in the Laminariales order. They can grow very large, and form dense beds. (in Merlin Dictionary)
Seaweed ashes, which were once used to make potash or iodine. (in Merlin Dictionary)