petrolatum, colorless to yellowish-white hydrocarbon mixture obtained by fractional distillation of petroleum. In its jellylike semisolid form (known as petroleum jelly and also by several trade names) it is used in preparing medicinal ointments and for lubrication. As a nearly colorless, highly refined liquid known as liquid petrolatum, liquid paraffin, or mineral oil, it is used as a lubricant, as a laxative, and as a base for nasal sprays.