From Longman Dictionary of Contemporary EnglishRelated topics: Geography, Geologyestuaryes‧tu‧a‧ry /ˈestʃuəri, -tʃəri $ -tʃueri/ noun (plural estuaries) [countable]SGthe wide part of a river where it goes into the sea → sourcethe Thames estuaryExamples from the Corpusestuary• All this at three o'clock in the morning in the middle of the most dangerousestuary in the country.• The noise of the incomingtide had interrupted their games on the sand further out in the estuary.• I should like to see the rivers that flow into the estuary - and indeed the entire Bristol channel - cleaned.• The results confirm the importance of the estuary for shelduck and identify particularly sensitive areas for breeding.• First enteringshallowequatorial seas, then estuaries and coastaloceans, the prehistoriccetaceansspread through the seas of the world.• He directs us to a good campsite a half mile down the beach at the base of a fresh-water estuary.Originestuary(1500-1600)Latinaestuarium, from aestus"boiling, tide"