Source : Webster's Revised Unabridged Dictionary (1913)

Hemibranchi \Hem`i*bran"chi\, n. pl. [NL. See {Hemi-}, and
   {Branchia}.] (Zo["o]l.)
   An order of fishes having an incomplete or reduced branchial
   apparatus. It includes the sticklebacks, the flutemouths, and
   Fistularia.