The Collaborative International Dictionary
Perisome
Perisome \Per"i*some\, n. [Pref. peri- + -some body.] (Zo["o]l.) The entire covering of an invertebrate animal, as echinoderm or c[oe]lenterate; the integument.
Wiktionary
perisome
n. (context biology English) The outer body of an invertebrate; the integument