rias From WikiWord, the free dictionary English Contents DefinitionsRelated wordsReferences DefinitionsnounA submergent coastal landform, often known as a drowned river valley Related wordsSynonymsariairsummaryriarbaisaaccountsestuariesinletsrievesrielribasriosribeirorieraraiaAssociatedisseimemhistsenhorafjordsmeanderingmachadoliaamorgalicia References Wiktionary — rias Wikipedia — rias