Source : WordNet®

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}]