noun.
A variety of Brassica oleracea, a cabbage with curled or wrinkled leaves which have no tendency to form into a hard head. It is valued chiefly for winter use.
the GNU version of the Collaborative International Dictionary of English
noun.
A brassicaceous plant of many varieties, cultivated for its leaves, which are not formed into a compact head like the cabbage, but are loose, and are generally curled or wrinkled; kale.