previously vs though

previously

adv
  • At an earlier time. 

  • Recapitulating the preceding episodes of a series. 

though

adv
  • Despite that; however. 

  • Used to intensify statements or questions; indeed. 

conj
  • Despite the fact that; although. 

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