step on vs tromp

step on

verb
  • Used other than figuratively or idiomatically: see step, on. 

  • to adulterate a drug for the purpose of increasing its bulk, and therefore its profit; to dilute, cut. 

tromp

verb
  • To tread heavily, especially to crush underfoot. 

  • To utterly defeat an opponent. 

noun
  • A blowing apparatus in which air, drawn into the upper part of a vertical tube through side holes by a stream of water within, is carried down with the water into a box or chamber below which it is led to a furnace. 

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