A yellowish volatile synthetic liquid C₅H₁₁NO₂ of commercial amyl alcohol and nitrous acid that is used medicinally as a vasodilator. It is rapidly absorbed by the body on inhalation, and is sometimes used recreationally especially as an aphrodisiac.
Any of several isomeric univalent hydrocarbon radicals, C₅H₁₁, formally derived from pentane by the loss of a hydrogen atom.