oddball vs oddity

oddball

noun
  • An eccentric or unusual person. 

  • A deviant stimulus that appears among repetitive stimuli during an experiment, to trigger an event-related potential in the participant. 

adj
  • Exotic, not mainstream. 

oddity

noun
  • A strange person; an oddball. 

  • Strangeness. 

  • An odd or strange thing or opinion. 

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