about turn vs digress

about turn

verb
  • To turn to face the opposite direction. 

noun
  • Of a formation of soldiers, to reverse the direction in which they are facing; an about face. 

  • A complete change of opinion, direction, etc. 

digress

verb
  • To turn aside from the right path; to transgress; to offend. 

  • To step or turn aside; to deviate; to swerve; especially, to turn aside from the main subject of attention, or course of argument, in writing or speaking. 

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