What is "nonyl"

Nonyl \Non"yl\, n. [Nonane + -yl.] (Chem.) The hydrocarbon radical, C9H19-, derived from nonane and forming many compounds. Used also adjectively; as, nonyl alcohol.

n. (context organic chemistry English) Any of very many isomeric univalent hydrocarbon radicals, C₉H₁₉, formally derived from nonane by the loss of a hydrogen atom.