Definify.com
Webster 1913 Edition
Petrolatum
Petˊro-la′tum
,Noun.
(Chem. & Pharm.)
A semisolid unctuous substance, neutral, and without taste or odor, derived from petroleum by distilling off the lighter portions and purifying the residue. It is a yellowish, fatlike mass, transparent in thin layers, and somewhat fluorescent. It is used as a bland protective dressing, and as a substitute for fatty materials in ointments.
U. S. Pharm.
☞
Petrolatum
is the official name for the purified product. Cosmoline
and vaseline
are commercial names for substances essentially the same, but differing slightly in appearance and consistency or fusibility.