资料来源 : Webster's Revised Unabridged Dictionary (1913)

Right whale \Right" whale`\ (Zo["o]l.)
   (a) The bowhead, Arctic, or Greenland whale ({Bal[ae]na
       mysticetus}), from whose mouth the best whalebone is
       obtained.
   (b) Any other whale that produces valuable whalebone, as the
       Atlantic, or Biscay, right whale ({Bal[ae]na
       cisarctica}), and the Pacific right whale ({B.
       Sieboldii}); a bone whale.

   {Pygmy right whale} (Zo["o]l.), a small New Zealand whale
      {(Neobal[ae]na marginata)} which is only about sixteen
      feet long. It produces short, but very elastic and tough,
      whalebone.

资料来源 : WordNet®

right whale
     n : large arctic whalebone whale; allegedly the `right' whale to
         hunt because of its valuable whalebone and oil