Epiphragm

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Epiphragm \Ep"i*phragm\, n. [Gr. ? a covering, lid, fr. ? to
     block up.] (Zo["o]l.)
     A membranaceous or calcareous septum with which some mollusks
     close the aperture of the shell during the time of
     hibernation, or estivation.
     [1913 Webster]