What is the meaning of "regular pitch" when applied to a propeller?
Ill assume you are asking the context of fixed pitch propellers. In which case "regular pitch" is either the standard pitch for the airframe in question or some mid range pitch to deliver average performance. There are usually various propeller options for a given aircraft:  


  There are two types of fixed-pitch propellers: climb and cruise.
  Whether the airplane has a climb or cruise propeller installed depends
  upon its intended use. The climb propeller has a lower pitch,
  therefore less drag. Less drag results in higher rpm and more
  horsepower capability, which increases performance during takeoffs and
  climbs, but decreases performance during cruising flight.


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