Source : Webster's Revised Unabridged Dictionary (1913)

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.

Source : WordNet®

ecdysis
     n : periodic shedding of the cuticle in arthropods or the outer
         skin in reptiles [syn: {molt}, {molting}, {moult}, {moulting}]
     [also: {ecdyses} (pl)]