'acetylenyl' originates from 'acetylene', specifically the word 'acetyl', where 'acet-' meant 'vinegar' and '-yl' is a suffix used in organic chemistry to denote a radical derived from a specified compound.

'acetylene' changed from the French word 'acétylène' and eventually became the modern English word 'acetylene'.

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