broach vs touch upon

broach

verb
  • To cause to turn sideways to oncoming waves, especially large or breaking waves (usually followed by to; also figurative). 

  • To make a hole in, especially a cask of liquor, and put in a tap in order to draw the liquid. 

  • To begin discussion about (something). 

  • To open, to make an opening into; to pierce. 

  • To break the surface of the water. 

  • To be turned sideways to oncoming waves, especially large or breaking waves. 

noun
  • A spire rising from a tower. 

  • A broad chisel for stone-cutting. 

  • An awl; a bodkin; also, a wooden rod or pin, sharpened at each end, used by thatchers. 

  • A spit-like start on the head of a young stag. 

  • The stick from which candle wicks are suspended for dipping. 

  • The pin in a lock which enters the barrel of the key. 

  • A spit for cooking food. 

  • A series of chisel points mounted on one piece of steel. For example, the toothed stone chisel shown here. 

touch upon

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