anvil vs roost

anvil

noun
  • A stone or other hard surface used by a bird for breaking the shells of snails. 

  • A horizontal-topped mass of cloud, shaped like a blacksmith's anvil, that forms before a thunderstorm. 

  • The non-moving surface of a micrometer against which the item to be measured is placed. 

  • A heavy iron block used in the blacksmithing trade as a surface upon which metal can be struck and shaped. 

  • The incus bone in the middle ear. 

verb
  • To fashion on, or as if on, an anvil. 

roost

noun
  • The place where a bird sleeps (usually its nest or a branch). 

  • A group of birds roosting together. 

  • A tidal race. 

  • A bedroom 

  • The inner roof of a cottage. 

verb
  • to spend the night 

  • To settle on a perch in order to sleep or rest 

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