acidophilicPronunciation: /ˌasɪdə(ʊ)ˈfɪlɪk, əˌsɪd-/Definition of acidophilic adjective Biology 1(of a cell or its contents) readily stained with acid dyes. 2(of a microorganism or plant) growing best in acidic conditions. acidophilic in other Oxford dictionaries Definition of acidophilic in the US English dictionary