upon

 
Pronunciation: /əˈpɒn/

preposition

  • more formal term for on, especially in abstract senses. it was based upon two principles a school’s dependence upon parental support

Origin:

Middle English: from up + on, suggested by Old Norse upp á

The preposition upon has the same core meaning as the preposition on. However, in modern English upon tends to be restricted to more formal contexts or to established phrases and idioms, as in once upon a time and row upon row of seats.