\Es"tu*a*ry\, n.; pl. {Estuaries}. [L. aestuarium, from
aestuare to surge. See {Estuate}.] [Written also
{[ae]stuary}.]
1. A place where water boils up; a spring that wells forth.
   [Obs.] --Boyle.
2. A passage, as the mouth of a river or lake, where the tide
   meets the current; an arm of the sea; a frith.
         it to the sea was often by long and wide estuaries.
                                               --Dana.

\Es"tu*a*ry\, a.
Belonging to, or formed in, an estuary; as, estuary strata.
--Lyell.