'aspartyl' originates from the adjective 'aspartic' (from New Latin/Modern Latin related to 'asparag-,' from Latin 'asparagus') combined with the chemical suffix '-yl' which denotes a radical or substituent group.

'aspartic' was named after 'asparagus' because the acid was first obtained from asparagus; the chemical formation 'aspartyl' developed in 19th-century chemical nomenclature by adding the suffix '-yl' to indicate the radical derived from aspartic acid, eventually yielding the modern term 'aspartyl'.

Initially associated with 'from asparagus' (the source of the acid), the term evolved to refer specifically to the acid (aspartic acid) and then to the radical or residue derived from that acid ('aspartyl').