'Filefish' definitions:

Definition of 'filefish'

(from WordNet)
noun
Narrow flattened warm-water fishes with leathery skin and a long file-like dorsal spine

Definition of 'Filefish'

From: GCIDE
  • Filefish \File"fish`\, n. (Zool.) Any plectognath fish of the genera Monacanthus, Alutera, balistes, and allied genera; -- so called on account of the roughly granulated skin, which is sometimes used in place of sandpaper. [1913 Webster]