explicit vs upfront

explicit

adj
  • Very specific, clear, or detailed. 

  • Containing material (e.g. language or film footage) that might be deemed offensive or graphic. 

noun
  • The final few words of a text. 

upfront

adj
  • Honest, frank and straightforward. 

  • In a forward, leading or frontward position. 

  • Paid in advance. 

adv
  • beforehand 

  • As an attacker. 

noun
  • A meeting of network executives with the press and major advertisers, signaling the start of advertising sales for a new season 

verb
  • To bring to the fore; to place up front for consideration 

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