Oxford Dictionary English estuary noun noun BrE BrE//ˈestʃuəri// ; NAmE NAmE//ˈestʃueri// (pl. estuaries) Rivers and lakes Add to my wordlistjump to other results enlarge image the wide part of a river where it flows into the sea the Thames estuary Wordfinderriverbend, course, current, dam, downstream, estuary, river, source, tributary, waterfall See related entries: Rivers and lakes Word Originmid 16th cent. (denoting a tidal inlet of any size): from Latin aestuarium ‘tidal part of a shore’, from aestus ‘tide’.See estuary in the Oxford Learner's Dictionary of Academic EnglishSee estuary in the Oxford Advanced American DictionaryCheck pronunciation: estuary oxfordlearnersdictionaries.com