'alkynyl' originates from 'alkyne', specifically the word 'alkyne', where 'alk-' referred to 'alkane' and '-yne' indicated a triple bond.

'alkyne' transformed into the term 'alkynyl' to denote the radical form, and eventually became the modern English word 'alkynyl'.

Initially, it meant 'a radical derived from an alkyne', and this meaning has largely remained the same in modern usage.