chancy vs on thin ice

chancy

adj

  • Subject to chance; random. 

  • Uncertain; risky; hazardous. 

on thin ice

prep

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

adv

  • dangerously, hazardously, delicately 

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