Loch is a word meaning "lake" or "sea inlet" in Scottish and Irish Gaelic, subsequently borrowed into English. In Irish contexts, it often appears in the anglicized form "lough".

Scottish Gaelic, also known as Scots Gaelic or simply Gaelic, is a Goidelic language native to the Gaels of Scotland. As a Goidelic language, Scottish Gaelic, as well as both Irish and Manx, developed out of Old Irish. It became a distinct spoken language sometime in the 13th century in the Middle Irish period, although a common literary language was shared by the Gaels of both Ireland and Scotland until well into the 17th century. Most of modern Scotland was once Gaelic-speaking, as evidenced especially by Gaelic-language place names.