In organic chemistry, the term acetylenic designates A doubly unsaturated position (sp-hybridized) on a molecular framework, for instance in an alkyne such as acetylene; An ethynyl fragment, HC ≡ {\displaystyle \equiv } C–, or substituted homologue. See also Allylic Propargylic Vinylic Loading related searches...Wikiwand - on Seamless Wikipedia browsing. On steroids.