developerPronunciation: /dɪˈvɛləpə(r)/Translate developer | into French | into German | into Italian | into Spanish Definition of developer noun a person or thing that develops something:a property developer software developers [with adjective] a person who grows or matures at a specified time or rate:I was a slow developer [mass noun] a chemical agent used for treating photographic film to make a visible image: photography paper in a trough of developerdeveloper in other Oxford dictionaries Definition of developer in the US English dictionary