pencil vs rough out

pencil

verb
  • To write (something) using a pencil. 

  • To mark with, or as if with, a pencil. 

noun
  • A paintbrush. 

  • A writing utensil with a graphite (commonly referred to as lead) shaft, usually blended with clay, clad in wood, and sharpened to a taper. 

  • A family of geometric objects with a common property, such as the set of lines that pass through a given point in a projective plane. 

  • An aggregate or collection of rays of light, especially when diverging from, or converging to, a point. 

rough out

verb
  • To produce (a plan, diagram etc.) in rough. 

  • To create the rough shape of a sculpture from a large block of wood, stone, etc. 

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