The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
A rorqual, especially Balaenoptera physalus of the Atlantic and Pacific coasts, that attains a length of about 21 meters (70 feet). Also called fin whale.