trichiurus

from The Century Dictionary.

• noun In ichthyology, the typical genus of Trichiuridæ; the hairtails: so called from the long filament in which the tail ends. The species are also called ribbon-fish. T. lepturus, the type species, is the silvery hairtail, or cutlasfish.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Zoöl.) A genus of fishes comprising the hairtails. See hairtail.