What is "heptyl"

Heptyl \Hep"tyl\, n. [Hepta- + -yl.] (Chem.) A compound radical, C7H15, regarded as the essential radical of heptane and a related series of compounds.

n. (context organic chemistry English) Either of many isomeric univalent hydrocarbon radicals, C₇H₁₅, formally derived from heptane by the loss of a hydrogen atom.