Finback \Fin"back`\, n. (Zo["o]l.)
Any whale of the genera {Sibbaldius}, {Bal[ae]noptera}, and
allied genera, of the family {Bal[ae]nopterid[ae]},
characterized by a prominent fin on the back. The common
finbacks of the New England coast are {Sibbaldius
tectirostris} and {S. tuberosus}.