1) Compound used in photography 2) Photo developing chemical 3) Photo developing compound 4) Photo developing powder 5) Photo-developing compound 6) Photographic chemical 7) Photographic developer 
Amidol is a colorless crystalline compound with the molecular structure C6H3(NH2)2OH. It is a dihydrogen chloride salt and is used as a photographic developer. It was introduced as a developing agent for photographic papers in 1892. It is unusual amongst developing agents as it works most effectively in slightly acid conditions rather than the str...
• (n.) A salt of a diamino phenol, C6H3(OH)(NH2)2, used as a developer.
Am'i·dol noun [ Amide + - ol as in alcohol .] (Photog. & Chem.) A salt of a diamino phenol, C 6 H 3 (OH)(NH 2 ) 2 , used as a developer. 
Soluble reducing agent which works at low pH values 
a colorless, crystalline powder, CHNO&multiplydot;2HCl, derived from phenol, used chiefly as a photographic developer.