Source : Webster's Revised Unabridged Dictionary (1913)

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.