enlightening vs unfriendly

enlightening

adj

  • Serving to enlighten. 

unfriendly

adj

  • Not friendly; hostile; mean. 

  • Unfavourable. 

noun

  • An enemy. 

adv

  • in an unkind or unfriendly manner; not as a friend 

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