meditation vs woolgathering

meditation

noun
  • A devotional exercise of, or leading to contemplation. 

  • A contemplative discourse, often on a religious or philosophical subject. 

  • Careful and thorough thought. 

  • A musical theme treated in a meditative manner. 

woolgathering

noun
  • Indulgence in idle fancies or daydreams. 

  • The gathering of fragments of wool torn from sheep by bushes, etc. 

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