cold fish vs obdurate

cold fish

noun
  • A heartless individual; a person lacking empathy and emotion. 

  • A sexual partner who, during sex, lacks vigor or emotional reciprocity. 

obdurate

adj
  • Hardened against feeling; hard-hearted. 

  • Stubbornly persistent, generally in wrongdoing; refusing to reform or repent. 

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