Gly Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. glycine; a colorless crystalline sweet watersoluble solid; the simplest amino acid used chiefly in organic synthesis and biochemical research Example Sentence Gly is the smallest of the 20 amino acids commonly found in proteins. Synonyms glycine; G; aminoacetic acid Antonyms salt Hear It! Say It! Write It! Gly Switch to cursive Start Share with your friends: