Scotland in the Early Middle Ages to be adopted for house building, often combining layers of stone with turf. Place-name evidence, particularly the use of the prefix "pit", meaning land or a field, suggests that the heaviest areas of Pictish settlement were in modern Fife, Perthshire, Angus, Aberdeen and around the Moray Firth, although later Gaelic migration may have erased some Pictish names from the record. Early Gaelic settlement appears to have been in the regions of the western mainland of Scotland between Cowal and Ardnamurchan, and the adjacent islands, later extending up the West coast in the 8th century. There is place name and archaeological
Firth which are not termed such – Likewise, in the Northern Isles, the words "firth" and "sound" are often used arbitrarily or interchangeably. Bluemull Sound for example, is very similar to some of the firths in the Shetland Islands. Firth Firth is a word in the Scots and English languages used to denote various coastal waters in Scotland and even a strait. In the Northern Isles, it more usually refers to a smaller inlet. It is linguistically cognate to "fjord" (both from Proto-Germanic *"ferþuz") which has a more constrained sense in English. Bodies of water named "firths" tend to be more