"Firsth" is a term used primarily in Scotland to describe usually a long narrow estuary,
often a fjord, and sometimes a strait. The
best known are those of the Forth, Tay, and Clyde; the Solway Firth, into
which several rivers drain; the Moray Firth, between the northeast tip of
Loch Ness and the North Sea; and the Pentland Firth, the strait between
northeast Scotland and the Orkney Islands.
|The Firth of Forth, near Edinburgh