buddy vs sis

buddy

verb
  • To assign a buddy, or partner, to. 

adj
  • Resembling a bud. 

noun
  • A partner for a particular activity. 

  • An informal and friendly address to a stranger; a friendly (or occasionally antagonistic) placeholder name for a person one does not know. 

  • A friend or casual acquaintance. 

pron
  • A person far removed from the conversation. 

sis

pron
  • she 

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