Noun
Any whale of the genera Sibbaldius, Balaenoptera, and allied genera, of the family Balaenopteridae, characterized by a prominent fin on the back. The common finbacks of the New England coast are Sibbaldius tectirostris and S. tuberosus.
Source: Webster's dictionaryFor the next month he remained on the Finback, and participated in the rescue of other pilots. Source: Internet