characteristic vs unique

characteristic

adj
  • Being a distinguishing feature of a person or thing. 

noun
  • A distinguishing feature of a person or thing. 

  • For a given field or ring, a natural number that is either the smallest positive number n such that n instances of the multiplicative identity (1) summed together yield the additive identity (0) or, if no such number exists, the number 0. 

  • The integer part of a logarithm. 

  • The distinguishing features of a navigational light on a lighthouse etc by which it can be identified (colour, pattern of flashes etc.). 

unique

adj
  • Particular, characteristic. 

  • Of a rare quality, unusual. 

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

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

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

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