unfriendly vs vicious

unfriendly

adj

  • Not friendly; hostile; mean. 

  • Unfavourable. 

adv

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

noun

  • An enemy. 

vicious

adj

  • Savage and aggressive. 

  • Violent, destructive and cruel. 

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