Definition of upon in US English:

upon

preposition

  • ‘it was based upon two principles’
    more formal term for on, especially in abstract senses
    ‘a school's dependence upon parental support’
    • ‘It's a radio show that's been going for year upon year but very few people listen to it.’
    • ‘An American ship came to the island upon which we were being kept and we were freed.’
    • ‘It now offers a new owner the chance to build upon its past and to reawaken it as a working estate.’
    • ‘It is a seed of hope within what you rightly describe as a society based upon violence.’
    • ‘This is exactly the kind of sportsmanship this great game of rugby union is built upon.’
    • ‘He is building a fan base upon the goodwill he has generated since taking over the club.’
    • ‘The head chef is the key foundation upon which the business is built as are all the staff.’
    • ‘He has also made sure that the club has a far wider range of players to call upon.’
    • ‘I will have to travel a distance to make it there and do not want to find it closed upon arrival.’
    • ‘They look upon him as a political sage, a voice of freedom, a speaker of truth to power.’
    • ‘I take it upon myself to guide her there, and follow the signs until we reach a doorway.’
    • ‘It also drew upon his undoubted gifts as a poet and his intuitive genius as an historian.’
    • ‘He'd taken it upon himself to go to a friend's house, but did not tell us he was going.’
    • ‘I am only qualified to speak on my own behalf so that is all my opinion can be based upon.’
    • ‘She had a core of inner strength and she could be relied upon if you really needed help or you were in a mess.’
    • ‘Part of the city and a theme park will be built upon artificial islands on the lake.’
    • ‘The pressure upon him is heavy, not least because everything is now out of his hands.’
    • ‘Taste is based upon a certain set of assumptions about what is good or bad in the world.’
    • ‘The worrying thing is how those in power interpret the way we vote and act upon it to stay in power.’
    • ‘Easter is almost upon us and with it will come the full blast of the tourist trade.’

Usage

The preposition upon has the same core meaning as the preposition on. Upon is sometimes more formal than on, however, and is preferred in the phrases once upon a time and upon my word, and in uses such as row upon row of seats and Christmas is almost upon us

Origin

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

Pronunciation

upon

/əˈpɑn//əˈpän/