One of two major divisions of modern-day Celtic languages (the other being Brythonic). Also known as Gaelic, or Q-Celtic for the way it uses a "C" or "K" to begin words that, in the hypothetical base Indo-european language, began with "Qu" (in contrast with Brythonic, which changed the sound much more severely to a "P").
The three Goidelic languages to survive into modern times are Irish Gaelic, Scots Gaelic, and Manx. Goidelic languages were once restricted to Ireland, but in the 6th century Irish colonists and invaders began migrating to Scotland and slowly pushed out the Brythonic language found there. Manx is in turn an offshoot of Scottish Gaelic, with heavy influence from Norse from the time the Isle of Man was controlled by Viking Scandinavians. Goidelic languages were once common on the western edge of Celtic Europe; there is also evidence that they were spoken in the region of Galicia in Spain.