Source : Webster's Revised Unabridged Dictionary (1913)

Labyrinthodont \Lab`y*rin"tho*dont\, a. (Paleon.)
   Of or pertaining to the Labyrinthodonta. -- n. One of the
   Labyrinthodonta.

Source : WordNet®

labyrinthodont
     n : an amphibian of the superorder Labyrinthodontia