riasnounfeminine/ˈʁiɐʃ/lowri·asPortuguesEnglishEspanolFrancaisDefinitionPlural of 'ria'. A long, narrow inlet of the sea on the coast, resulting from the submersion of a river valley.The rias of Minho are known for their natural beauty.The northwest coast of Portugal is marked by several rias.synriasinletsestuariesEtymologyDo galego-português 'ria', do latim 'rivus' (riacho).Related wordsria