a branch of the Indo-European family of languages, including especially Irish, Scottish Gaelic, Welsh, and Breton, which survive now in Ireland, the Scottish Highlands, Wales, and Brittany. adjective. 2. of the Celts or their languages.
Movement of tectonic plates-higher. Volcanoes, mountains and earthquakes occur at the edges of tectonic plates-their creation depends on the direction the plates are moving.
Plate tectonic movement can cause the formation of volcanic islands. Mountains, such as Mt. Everest, are created when tectonic plates push against each other. Continental drift, a forerunner of plate tectonics, explained how the current continents once likely fit together.