black whale
       n 1: small dark-colored whale of the Atlantic coast of the United
            States; the largest male acts as pilot or leader for the
            school [syn: pilot whale, common blackfish, blackfish,
             Globicephala melaena]
       2: large whale with a large cavity in the head containing
          spermaceti and oil; also a source of ambergris [syn: sperm
          whale, cachalot, Physeter catodon]