ophiuroid Syllabification: (oph·i·ur·oid)Pronunciation: /ˌäfēˈyo͝oroid, ˌōfē-/ ZoologyDefinition of ophiuroid noun an echinoderm of the class Ophiuroidea, which comprises the brittlestars. adjective relating to or denoting ophiuroids. ophiuroid in other Oxford dictionaries Definition of ophiuroid in the British & World English dictionary