already vs previously

already

adv
  • Prior to some specified time, either past, present, or future; by this time; previously. 

  • An intensifier used to emphasize impatience or express exasperation. 

  • So soon. 

previously

adv
  • At an earlier time. 

  • Recapitulating the preceding episodes of a series. 

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