1) Amino acid 2) Photographic chemical 
Glycin, or N-(4-hydroxyphenyl)glycine, is N-substituted p-aminophenol. It is a photographic developing agent used in classic black-and-white developer solutions. It is unrelated to the amino acid glycine. When fresh, it is typically characterized as thin plates of white or silvery powder, turning brown with age. It is sparingly soluble in water an...
• (n.) Same as Glycocoll.
Gly'cin noun [ Greek