Placophora Copy link Placophora (plȧ*kof"o*rȧ) , noun, plural [New Latin, from Greek pla`x, plako`s, tablet + fe`rein to bear.] (Zoology) A division of gastropod Mollusca, including the chitons. The back is covered by eight shelly plates. Called also Polyplacophora. See Illust. under Chiton, and Isopleura.