as in vs why

as in

adv
  • Used other than figuratively or idiomatically: see as, in. 

  • In the sense of. 

why

adv
  • Introducing a noun or other phrase. 

  • For which cause, reason, or purpose. 

  • The cause, reason, or purpose for which. 

  • Introducing a verb phrase (bare infinitive clause). 

  • Introducing a complete question. 

  • With a negative, used rhetorically to make a suggestion. 

intj
  • An exclamation used to express pleasant or unpleasant mild surprise, indignation, or impatience. 

noun
  • Reason. 

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