a colorless, volatile liquid, CH:C(CH)CH:CH, prepared by the dry distillation of raw rubber or synthetically: when heated with sodium or other substances it polymerizes to form a substance closely resembling natural rubber
Origin:
coined (1860) by C. G. Williams (1829-1910), Brit chemist < iso- + pr(opyl) + -ene
See isoprene in American Heritage Dictionary 4
noun
A colorless volatile liquid, C5H8, used chiefly to make synthetic rubber.