Source : Webster's Revised Unabridged Dictionary (1913)

Branchial \Bran"chi*al\, a. (Anat.)
   Of or pertaining to branchi[ae] or gills.

   {Branchial arches}, the bony or cartilaginous arches which
      support the gills on each side of the throat of fishes and
      amphibians. See Illustration in Appendix.

   {Branchial clefts}, the openings between the branchial arches
      through which water passes.

Cleft \Cleft\, n. [OE. clift; cf. Sw. klyft cave, den, Icel.
   kluft cleft, Dan. kl["o]ft, G. kluft. See {Cleave} to split
   and cf. 2d {Clift}, 1st {Clough}.]
   1. A space or opening made by splitting; a crack; a crevice;
      as, the cleft of a rock. --Is. ii. 21.

   2. A piece made by splitting; as, a cleft of wood.

   3. (Far.) A disease in horses; a crack on the band of the
      pastern.

   {Branchial clefts}. See under {Branchial}.

   Syn: Crack; crevice; fissure; chink; cranny.