• (a.) Discoidal by derivation; -- applied especially to the placenta of man and apes, because it is supposed to have been derived from a diffused placenta.
Met`a·dis·coid'al adjective [ Meta- + discoidal .] (Anat.) Discoidal by derivation; -- applied especially to the placenta of man and apes, because it is supposed to have been derived from a diffused placenta.