Interoperculum \In`ter*o*per"cu*lum\, n.; pl. {-la} (-l[.a]). (Anat.) The postero-inferior opercular bone, in fishes. Peplum \Pep"lum\, n.; pl. E. {-lumus}, L. {-la}. [L.] A peplos. Hence: An overskirt hanging like an ancient peplos; also, a short fitted skirt attached to a waist or coat.