actinostome
/ˈaktɪnə(ʊ)ˌstəʊm/Zoology
noun
The mouth or oral opening of a radiate animal, such as a coelenterate or (now usually) an echinoderm.
Origin
Mid 19th century; earliest use found in Louis Agassiz (1807–1873), zoologist and geologist. From actino- + -stome.