That which provides a reason or justification
A fact or circumstance that gives logical support to an assertion, claim, or proposal
  1. for what reason?
  2. how-so
  3. how
  4. how is it that?
  5. on whose account?
  6. what is the cause that?
  7. to-what-end
  8. for what purpose
  9. on what foundation?
  10. how do you explain that?
  11. how-come

Words Related to Why

Related words are words that are directly connected to each other through their meaning, even if they are not synonyms or antonyms. This connection may be general or specific, or the words may appear frequently together.