Loch (pron.: / /, also the non-standard but common / /), is the Scottish Gaelic and Irish word for a lake or a sea inlet. In Ireland it has been anglicised as lough, although this is pronounced the same way as loch. Some lochs could also be called a firth, fjord, estuary, strait or bay. Sea-inlet lochs are often called sea lochs or sea loughs. It is cognate with the Manx logh and the now obsolete Welsh word for lake, llwch.
This name for a body of water is Goidelic in origin and is applied to most lakes in Scotland and to many sea inlets in the west and north of Scotland. The word is Indo-European in origin; cf. Latin lacus, English ' lake'.
Lowland Scots orthography, like Scottish Gaelic and Irish, represents / x/ with ch, so the word was borrowed with identical spelling.
English borrowed the word separately from a number of lochs in Northumbria and Cumbria. Earlier forms of English included the sound /x/ as gh (compare Scots bricht with English bright). This form was therefore used when the English settled Ireland. However, by the time Scotland and England joined under a single parliament, English had lost the /x/ sound, so the Scots convention of using CH remained, hence the modern Scottish English loch.
Many of the lochs in Northern England have also previously been called "meres" (a Northern English dialect word for "lake" and an archaic Standard English word meaning "a lake that is broad in relation to its depth") such as the Black Lough in Northumberland. However, reference to the latter as lochs or loughs (lower case initial), rather than as lakes, inlets and so on, is unusual.
Although there is no strict size definition, a small loch is often known as a lochan (so spelled also in Scottish Gaelic; in Irish it is spelled lochán).
Perhaps the most famous Scottish loch is Loch Ness, although there are other large examples such as Loch Awe, Loch Lomond and Loch Tay.
Examples of sea lochs in Scotland include Loch Long, Loch Fyne, Loch Linnhe, Loch Eriboll, Loch Tristan, Trisloch.
Uses of lochs
Some new reservoirs for hydroelectric schemes have been given names faithful to the names for natural bodies of water - for example: the Loch Sloy scheme, and Lochs Laggan and Treig (which form part of the Lochaber hydroelectric scheme near Fort William). Other expanses are simply called reservoirs, e.g.: Blackwater Reservoir above Kinlochleven.
Scotland has very few natural water bodies actually called 'lakes'. The Lake of Menteith, an Anglicisation of the Scots Laich o Menteith meaning a "low-lying bit of land in Menteith", and applied to the loch there because of the similarity of the sounds of the words laich and lake. The Lake of the Hirsel, Pressmennan Lake and Lake Louise are other bodies of water in Scotland which are called lakes and all are man-made.
The word "loch" is sometimes used as a shibboleth to identify natives of England, because the fricative [ x] sound is used in Scotland whereas most English people incorrectly pronounce the word like "lock".
Lochs beyond Scotland and Ireland
As "loch" is a common Gaelic word, it is also found as the root of several Manx placenames.
The United States naval port of Pearl Harbour, located on the south coast of the main Hawaiian island of Oahu, is one of a complex of sea inlets. Several of these are named as lochs, viz. South East Loch, Merry Loch, East Loch, Middle Loch and West Loch.
Loch Raven Reservoir is a reservoir in Baltimore County, Maryland.
Brenton Loch in the Falkland Islands is a sea loch, near Lafonia, East Falkland.
In the Scottish settlement of Glengarry County in present day Eastern Ontario, there is a lake called Loch Garry. Loch Garry is named by the settlers that settled in the area, Clan MacDonell of Glengarry after the well known loch where their clan is from Loch Garry in Scotland.