assured vs on thin ice

assured

noun
  • An insured person. 

adj
  • Guaranteed; secure. 

  • Self-confident; self-assured; sure. 

on thin ice

prep
  • In a dangerous, hazardous, or delicate situation; at risk. 

adv
  • dangerously, hazardously, delicately 

How often have the words assured and on thin ice occurred in a corpus of books? (source: Google Ngram Viewer )