killer language

English

Etymology

The phrase was first used by Anne Pakir in 1991 in reference to English.

Noun

killer language (plural killer languages)

1. (linguistics) A dominant and prestigious language which gradually causes extinction of other, especially minor languages.
   • 2012, Danny Hieber, Mises Daily, Why Do Languages Die?‎:

     It is only when the state adopts a trade language as official and, in a fit of linguistic nationalism, foists it upon its citizens, that trade languages become "killer languages."