double-faced vs untruthful

double-faced

adj
  • deceitful; hypocritical; treacherous 

  • Having two functional faces. 

untruthful

adj
  • Pertaining to falsehood; corrupt; dishonest. 

  • Not giving the truth; providing untrue facts; lying. 

How often have the words double-faced and untruthful occurred in a corpus of books? (source: Google Ngram Viewer )