unbolt vs unsnib

unbolt

verb
  • To unlock by undoing the bolts of. 

unsnib

verb
  • to undo, untie, or open or become undone, untied, or opened. 

  • Somehow she managed to unsnib the window and escape. 

How often have the words unbolt and unsnib occurred in a corpus of books? (source: Google Ngram Viewer )