blabber vs let something slip

blabber

verb

  • To blab; to reveal a secret. 

  • To blather; to talk foolishly or incoherently. 

noun

  • A person who blabs; a tattler; a telltale. 

let something slip

verb

  • To accidentally reveal a secret. 

How often have the words blabber and let something slip occurred in a corpus of books? (source: Google Ngram Viewer )