Longman Dictionary English From Longman Dictionary of Contemporary EnglishRelated topics: ChemistrypHpH /piː ˈeɪtʃ/ (also pH value) noun [singular] HCa number on a scale of 0 to 14 which shows how acid or alkaline a substance is → litmus testpH of soil with a pH of 3.1Origin pH (1900-2000) German potenz “power” + H, sign for hydrogen ldoceonline.com
