batten down vs untie

batten down

verb
  • To close or make watertight, referring to hatches and cargo. 

  • To secure. 

  • To prepare for adversity. 

untie

verb
  • To loosen, as something interlaced or knotted; to disengage the parts of. 

  • In the Perl programming language, to undo the process of tying, so that a variable uses default instead of custom functionality. 

  • To resolve; to unfold; to clear. 

  • To become untied or loosed. 

  • To free from fastening or from restraint; to let loose; to unbind. 

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