'glycinic' originates from the noun 'glycine' plus the adjectival suffix '-ic'; 'glycine' itself was named from Greek 'glykys' meaning 'sweet', referring to the sweet taste of the amino acid.

'glycine' was coined in the early 19th century (from French/Neo-Latin forms based on Greek 'glykys'), and the chemical adjective 'glycinic' was formed later by adding the suffix '-ic' to denote 'pertaining to' or 'derived from' glycine.

Initially it referred specifically to the sweet substance (glycine) or compounds derived from it; over time it has come to be used generally as a chemical adjective meaning 'of or relating to glycine'.