The term PT. OF RPM stands for 'Pulse Time of Revolutions Per Minute'. It is a measure of the speed of rotation of an object, such as a motor or wheel. The crossword solution REV is an abbreviation for revolution, which is the number of times an object rotates around its own axis in a given period of time. Therefore, PT. OF RPM is a measure of the amount of time it takes for an object to make one full rotation.