| Estuary 1. (n.) The mouth of a river where the tide meets the current; an arm of the sea. 2. (n.) A place where water boils up; a spring that wells forth. 3. (a.) Belonging to, or formed in, an estuary; as, estuary strata. Thesaurus Entries arm, armlet, avenue, bay, bayou, belt, bight, blowhole, boca, channel, chute, cove, creek, debouch, door, egress, emunctory, escape, euripus, exhaust, exit, fjord, floodgate, flume, frith, gulf, gut, harbor, inlet, kyle, loch, loophole, mouth, narrow, narrow seas, narrows, natural harbor, opening, out, outcome, outfall, outgate, outgo, outlet, pore, port, reach, road, roads, roadstead, sally port, sluice, sound, spiracle, spout, strait, straits, tap, vent, ventage, venthole, vomitory, way out, weir |