a. (Zool.) Pertaining to the Placoganoidei. [ 1913 Webster ]

‖n. pl. [ NL., fr. Gr. pla`x, plako`s, a tablet + NL. ganoidei. See Ganoidei. ] (Zool.) A division of ganoid fishes including those that have large external bony plates and a cartilaginous skeleton. [ 1913 Webster ]