stepper vs tread

stepper

noun
  • A shoe, especially a fashionable or attractive shoe, or one used for step-dancing. 

  • A device used in the manufacture of microcircuits to apply a photolithographic image repeatedly, at regular intervals (by imaging, moving a step and repeating). 

  • A person or animal that steps, especially energetically or high. 

  • A dancer. 

  • A type of exercise machine. 

  • Anything that moves or advances in steps. 

  • A kind of electric motor (a stepper motor) that advances in steps rather than smoothly. 

  • A dancer in a step show. 

tread

noun
  • The grooves on the bottom of a shoe or other footwear, used to give grip or traction. 

  • A step taken with the foot. 

  • The grooves carved into the face of a tire, used to give the tire traction. 

  • The chalaza of a bird's egg; the treadle. 

  • A bruise or abrasion produced on the foot or ankle of a horse that interferes, or strikes its feet together. 

  • The horizontal part of a step in a flight of stairs. 

  • The top of the banquette, on which soldiers stand to fire over the parapet. 

  • The act of avian copulation in which the male bird mounts the female by standing on her back. 

  • A manner of stepping. 

  • The sound made when someone or something is walking. 

verb
  • To proceed, to behave (in a certain manner). 

  • To beat or press with the feet. 

  • To work a lever, treadle, etc., with the foot or the feet. 

  • To crush grapes with one's feet to make wine 

  • To step or walk upon. 

  • To copulate; said of (especially male) birds. 

  • To step or walk (on or across something); to trample. 

  • To go through or accomplish by walking, dancing, etc. 

  • To copulate with. 

  • To crush under the foot; to trample in contempt or hatred; to subdue. 

How often have the words stepper and tread occurred in a corpus of books? (source: Google Ngram Viewer )