Home › Words › U › unioidunioidunioid means resembling or characteristic of the unios.Among words judged in Lexicurio's Arena, unioid ranks #36,606 of 42,747 for Qualifying.EtymologyFrom unio + -oid. Compare unionoid.adjResembling or characteristic of the unios.nounSynonym of unionoid.Definitions & examples from Wiktionary (CC BY-SA 3.0).