The Collaborative International Dictionary
Polymorphosis
Polymorphosis \Pol`y*mor*pho"sis\, n. [NL. See Poly-, and Morphosis.] (Zo["o]l.) The assumption of several structural forms without a corresponding difference in function; -- said of sponges, etc.
Wiktionary
polymorphosis
n. (context zoology English) The assumption of several structural forms without a corresponding difference in function; -- said of sponges, etc.