Ecdysis \Ec"dy*sis\, n.; pl. {Ecdyses}. [NL., fr. Gr. 'e`kdysis a getting out, fr. 'ekdy`ein, to put off; 'ek out + dy`ein to enter.] (Biol.) The act of shedding, or casting off, an outer cuticular layer, as in the case of serpents, lobsters, etc.; a coming out; as, the ecdysis of the pupa from its shell; exuviation. [1913 Webster]