a cappella vs hermit

a cappella

adv
  • In a manner of a choir with no instrumental accompaniment; literally, "in the style of the (Sistine) Chapel (in Rome)", such as a musical Mass done a cappella. 

adj
  • Singing solely or mainly without instrumental accompaniment. 

  • Related to a form of purely vocal music mostly associated with American college performance groups. 

noun
  • A vocal performance with no instrumental accompaniment. 

hermit

noun
  • A religious recluse; someone who lives alone for religious reasons; an eremite. 

  • A spiced cookie made with molasses, raisins, and nuts. 

  • A recluse; someone who lives alone and shuns human companionship. 

  • A hermit crab. 

  • Any in the subfamily Phaethornithinae of hummingbirds. 

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