The American Heritage® Dictionary of the English Language, 4th Edition
n. 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.
n. A large baleen whale, Balaenoptera physalus, that has a ridge on its back; the fin whale.
the GNU version of the Collaborative International Dictionary of English
n. Any whale of the genera Sibbaldius, Balænoptera, and allied genera, of the family Balænopteridæ, characterized by a prominent fin on the back. The common finbacks of the New England coast are Sibbaldius tectirostris and S. tuberosus.
The Century Dictionary and Cyclopedia
n. A finner or fin-whale.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. large flat-headed whalebone whale having deep furrows along the throat; of Atlantic and Pacific
Word Usage
""What's the difference between a 'finback' and a 'humpback,' Hank?" asked the boy, after the canvas had been stowed, the vessel under auxiliary steam having speed enough to keep up with the cetaceans, "are they 'right' whales?""