'glycinyl' originates from the New Latin/chemical formation based on 'glycine' + the organic-chemistry suffix '-yl' (a suffix denoting a radical or substituent). 'Glycine' itself ultimately comes from Greek 'glykys' meaning 'sweet'.

'glycinyl' developed by attaching the 19th-century chemical suffix '-yl' to the name 'glycine' (which entered scientific Latin/French from Greek); related earlier forms include the shorter variant 'glycyl', and both forms have been used in chemical literature before 'glycinyl' became established in some nomenclatures.

Initially the root referred to 'related to glycine' or simply the amino acid glycine; over time the term specialized to denote specifically a radical/substituent or residue derived from glycine in organic and peptide chemistry.