noun
: an efflorescent crystalline or powdery compound C 10 H 18 (OH) 2 .H 2 O formed from cis -terpene by absorption of water, obtained usually from turpentine oil or alpha-pinene by hydration with dilute acids or from pine oil by steaming the residual rosin, and used as an expectorant for a cough and as an intermediate in making terpineol