What is "ethynyl"

n. (context organic chemistry English) The univalent radical HC≡C- derived from acetylene

In organic chemistry the term ethynyl may refer to any of the following concepts:

• The ethynyl group (HC≡C–), also designated as acetylenic group (from acetylene), and referred to in IUPAC chemical nomenclature as -yne suffix. Also sometimes designed as Ethinyl in compounds (example: ethinyl estradiol). See Alkynes.
• The ethynyl radical (HC≡C·), the compound found in interstellar medium, and transiently on earth during chemical reactions.
• The ethynyl carbanion acetylide (HC≡C)