The Gaelic-speaking parts of Scotland, considered collectively; especially the Highlands and Hebrides. Also: any of several areas in Canada in which Scottish Gaelic is spoken. Now usually with the. Compare "Gaeltacht", "Gaeldom".
Late 19th century; earliest use found in Celtic Magazine. From Scottish Gaelic Gàidhealtachd Gaelic-speaking people collectively, Gaelic-speaking area, now also denoting the Highlands more generally (e.g. in the name of the Highland Council Area), cognate with or formed similarly to Irish Gaeltacht.