estray vs wander

estray

noun
  • An animal that has escaped from its owner; a wandering animal whose owner is unknown. An animal cannot be an estray when on the range where it was raised, and permitted by its owner to run. A lost animal whose owner is known to the party at hand is not an estray. 

wander

noun
  • An act or instance of wandering. 

  • The situation where a value or signal etc. deviates from the correct or normal value. 

verb
  • To go somewhere indirectly or at varying speeds; to move in a curved path. 

  • To move without purpose or specified destination; often in search of livelihood. 

  • Of the mind, to lose focus or clarity of argument or attention. 

  • To stray; stray from one's course; err. 

  • To commit adultery. 

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