nonene

from The Century Dictionary.

• noun A name given to two hydrocarbons, C₉H₁₈. One is obtained by heating 4-ethyl-4-iodohep-tane with alcoholic potash and boilsat 139.5° C. The other is CH₃C(C₆H₁₃): CH₂, which is obtained by heating the corresponding hydrochlorid of nonylamine. It boils at 141–143° C.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun organic chemistry Any of very many isomeric alkenes having nine carbon atoms