From Longman Dictionary of Contemporary Englishestuaryes‧tu‧a‧ry /ˈestʃuəri, -tʃəri $ -tʃueri/ noun (plural estuaries) [countable] SGthe wide part of a river where it goes into the sea → source the Thames estuary
Examples from the Corpus
estuary• All this at three o'clock in the morning in the middle of the most dangerous estuary in the country.• Hong Kong was just across the Pearl estuary, within clear broadcast range.• The noise of the incoming tide 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 entering shallow equatorial seas, then estuaries and coastal oceans, the prehistoric cetaceans spread 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.Origin estuary (1500-1600) Latin aestuarium, from aestus “boiling, tide” 