hexylene

from The Century Dictionary.

• noun A colorless liquid, CH₃(CH₂)₃CH: CH₂, prepared from hexyl chlorid and formed during the distillation of boghead coal or from superheated paraffin. It boils at. 68–70° C. Also called 5 -hexene.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Chem.) A colorless, liquid hydrocarbon, C6H12, of the ethylene series, produced artificially, and found as a natural product of distillation of certain coals; also, any one several isomers of hexylene proper. Called also hexene.

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

• noun chemistry A colourless liquid hydrocarbon, C6H12, of the ethylene series, produced artificially, and found as a natural product of distillation of certain coals.
• noun chemistry Any of several isomers of hexylene proper.