characteristic vs singular

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.). 

singular

adj
  • Being the only one of the kind; unique. 

  • Referring to only one thing or person. 

  • Distinguished by superiority: peerless, unmatched, eminent, exceptional, extraordinary. 

  • Having the property that the matrix of coefficients of the new variables has a determinant equal to zero. 

  • Out of the ordinary; curious. 

  • Each; individual. 

  • Being only one of a larger population. 

  • Not equal to its own cofinality. 

  • Having no inverse. 

noun
  • A form of a word that refers to only one person or thing. 

  • That which is not general; a specific determinate instance. 

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