It is derived from the French parer to parry, and chute a fall.
"The Mastery of the Air"
William J. Claxton
Robert del parer Perrier Old Fr.
"The Romance of Names"
Ernest Weekley
13. Count the cogs on the wheels of a fanning-mill, washing-machine, apple-parer, or egg-beater, and determine how the direction or rate of the motion is changed thereby.
"Ontario Teachers' Manuals: Nature Study"
Ontario Ministry of Education