/prəˌlɪfəˈreɪʃn/

•  n. [in general] ugaritze; [especially living beings] ugaltze

  Nuclear Non-Proliferation Treaty: Arma Nuklearrak Ez Ugaritzeko Hitzarmena

  the proliferation of pathogenic germs: germen patogenoak ugaltzea

  the proliferation of nuclear weapons: arma nuklearrak ugaritzea