guidepost vs lodestar

guidepost

noun
  • Anything that provides guidance; a guideline. 

  • A signpost. 

lodestar

noun
  • A guiding tenet or principle. 

  • A star used as a navigation reference, particularly a pole star such as Polaris. 

  • A calculated amount to award as attorney's fees derived by multiplying the reasonable number of hours spent working on a case by the reasonable hourly billing rate. 

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