give away vs let cat out of the bag

give away

verb
  • To concede. 

  • To formally hand over a bride to the bridegroom; often by her father. 

  • To relinquish control over. 

  • To concede an advantage in weight, time, height etc. 

  • To unintentionally reveal a secret, divulge undisclosed information, or expose someone. 

  • To make a gift of (something). 

let cat out of the bag

How often have the words give away and let cat out of the bag occurred in a corpus of books? (source: Google Ngram Viewer )