alone vs unique

alone

adj
  • By oneself, solitary. 

  • Lacking peers who share one's beliefs, experiences, practices, etc. 

adv
  • Not requiring anything further; merely. 

  • By oneself; apart from, or exclusive of, others; solo. 

  • Without outside help. 

  • Used to emphasize the size or extent of something by selecting a subset. 

  • Not permitting anything further; exclusively. 

unique

adj
  • Being the only one of its kind; unequaled, unparalleled or unmatched. 

  • Of a rare quality, unusual. 

  • Of a feature, such that only one holder has it. 

  • Particular, characteristic. 

noun
  • A thing without a like; something unequalled or unparallelled; one of a kind. 

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