Sprachbund

A sprachbund (/ˈsprɑːkbʊnd/; German: Sprachbund [ˈʃpʁaːxbʊnt] ^ⓘ, lit. "language federation"), also known as a linguistic area, area of linguistic convergence, or diffusion area, is a group of languages that share areal features resulting from geographical proximity and language contact. The languages may be genetically unrelated, or only distantly related, but the sprachbund characteristics might give a false appearance of relatedness.

A grouping of languages that share features can only be defined as a sprachbund if the features are shared for some reason other than the genetic history of the languages. Without knowledge of the history of a regional group of similar languages, it may be difficult to determine whether sharing indicates a language family or a sprachbund.^[1]