Sprachbund
A sprachbund ( SPRAHK-buund, from German: Sprachbund [ˈʃpʁaːxbʊnt] , lit. 'language federation'; pl. sprachbünde or sprachbunds), 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.