abnormal vs unfamiliar

abnormal

noun
  • A person or object that is not normal. 

adj
  • Of or pertaining to that which is irregular, in particular, behaviour that deviates from norms of social propriety or accepted standards of mental health. 

  • Not conforming to rule or system; deviating from the usual or normal type. 

unfamiliar

noun
  • An unfamiliar person; a stranger. 

adj
  • Strange, not familiar. 

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