estuary, æstuar, estuarie

& a. [Lat. æstuarium=a creek; æstuo = to surge, to foam; æstus =the tide.] A. As substantive : *I. Ord. Lang .: A place where water, ., boils up. "Over the estuary , or in some neighboring part of the place, where the mineral water springs." -Boyle: Works, 799. II. Technically : 1. Geog .: An arm of the sea; the mouth of a river, ., in which the tide meets the current, or ebbs and flows; a firth. "The dreary strand of the estuary of the Laggan."Macaulay: Hist . Eng ., ch. xvi. 2. Geol.: Most estuaries were formed at first by the combined influence of rivers seeking exit into the adjacent ocean, and tides from that ocean forcing themselves up the channel inland. The same causes which formed an estuary at first tend to keep it open. Both the tide and the river current in their mutual encounter are laden with sediment which, as long as the struggle between them is balanced, tends to be deposited, forming a bar at the river's mouth, but on the ebb of the tide the river current, hitherto dammed up as by an embankment, rushes out to sea with unchecked violence, carrying all or most of the deposited sediment to a great distance. Estuaries, though in the main keeping their channels open, yet here and there partially fill up where eddies exist. But this gain of land does not nearly compensate for the immense quantity carried out to sea. Freshwater species of animals and plants are imbedded in modern estuaries. B. As adjective : 1. Biol .: Living in an estuary. (Often used of shells.) "One very common estuary shell."-Woodward: Mol lusca (ed. Tate ), p. 48. 2. Geol .: Belonging to or formed in an estuary. (Used of strata.) es-tu-āte, v . i . [Lat. æstuoto boil, to surge.] To boil up, to swell, to be in a state of commotion; to rage and swell.