Meaning of positive crankcase ventilation

pos'itive crank'case ventila"tion

Pronunciation: [key]
— Auto. Auto.
  1. a means of reducing air pollution by directing the fumes from the crankcase of an engine into the intake manifold, so that they will be channeled into the cylinders and burned. Abbr.: PCV
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.