anyhow vs periodically

anyhow

adv
  • In any way or manner whatever. 

  • In any case. Used to indicate that a statement explains or supports a previous statement. 

periodically

adv
  • In a manner that is regular or periodic. 

  • intermittently or recurrently 

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