underbrush vs willow

underbrush

noun
  • The small trees and other plants that clutter the floor of a forest. 

verb
  • To clear (an area) of underbrush. 

  • To work among the underbrush. 

willow

noun
  • The wood of these trees. 

  • Any of various deciduous trees or shrubs in the genus Salix, in the willow family Salicaceae, found primarily on moist soils in cooler zones in the northern hemisphere. 

  • The baseball bat. 

  • A cricket bat. 

  • A rotating spiked drum used to open and clean cotton heads. 

verb
  • To form a shape or move in a way similar to the long, slender branches of a willow. 

  • To open and cleanse (cotton, flax, wool, etc.) by means of a willow. 

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