·noun One who, or that which, develops.
II. Developer ·add. ·noun One that develops.
III. Developer ·add. ·noun A chemical bath or reagent used in developing photographs.
IV. Developer ·add. ·noun A reagent used to produce an ingrain color by its action upon some substance on the fiber.
V. Developer ·noun A reagent by the action of which the latent image upon a photographic plate, after exposure in the camera, or otherwise, is developed and visible.