noun.
The part of the wide lower course of a river where its current is met by the tides.
noun.
An arm of the sea that extends inland to meet the mouth of a river.
The Century Dictionary and Cyclopedia
noun.
An arm or inlet of the sea, particularly one that is covered by water only at high tide.
noun.
That part of the mouth or lower course of a river flowing into the sea which is subject to tides; specifically, an enlargement of a river channel toward its mouth in which the movement of the tides is very prominent.
noun.
A place where water boils up.
Belonging to or formed in an estuary: as, estuary strata.
the GNU version of the Collaborative International Dictionary of English
adjective.
Belonging to, or formed in, an estuary.
noun.
A place where water boils up; a spring that wells forth.
noun.
A passage, as the mouth of a river or lake, where the tide meets the current; an arm of the sea; a frith.