Wikipedia
Gaelicisation
Gaelicisation, or Gaelicization, is the act or process of making something Gaelic, or gaining characteristics of the Gaels. The Gaels are an ethno-linguistic group, traditionally viewed as having spread from Ireland to Scotland and the Isle of Man.
"Gaelic", as a linguistic term, refers to the Gaelic languages but can also refer to the transmission of any other Gaelic cultural feature such as social norms and customs, music and sport.
It is often referred as a part of Celtic identity as Ireland, Scotland and the Isle of Man are all considered Celtic Nations, and the Gaelic languages are considered a sub-group of the Celtic languages, which many, such as Welsh, have also undergone Celticisation.