upon

American  

[uh-pon, uh-pawn] / əˈpɒn, əˈpɔn /

preposition

1. up and on; upward so as to get or be on.

   He climbed upon his horse and rode off.

2. in an elevated position on.

   There is a television antenna upon every house in the neighborhood.

3. in or into complete or approximate contact with, as an attacker or an important or pressing occasion.

   The enemy was upon us and our soldiers had little time to escape. The Christmas holiday will soon be upon us and we have hardly begun to buy gifts. The time to take action is upon us.

4. immediately or very soon after.

   She went into mourning upon her husband's death.

5. on the occasion of.

   She was joyful upon seeing her child take his first steps.

6. on (in any of various senses, used as an equivalent of on with no added idea of ascent or elevation, and preferred in certain cases only for euphonic or metrical reasons).

   He swore upon his honor as a gentleman.

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upon British  

/ əˈpɒn /

preposition

1. another word for on

2. indicating a position reached by going up

   climb upon my knee

3. imminent for

   the weekend was upon us again

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upon Idioms  

1. see act on (upon); call on (upon); chance on (upon); come across (upon); come on (upon); count on (upon); dawn on (upon); dwell on (upon); enter on (upon); fall back on (upon); fall on (upon); grow on (upon); hard on (upon); hit on (upon); incumbent upon; light on (upon); once upon a time; pitch on (upon); play on (upon); put upon; seize on (upon); set at (upon); take it upon oneself; wait on (upon); weigh on (upon); work on (upon).

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Etymology

Origin of upon

First recorded in 1150–1200; Middle English; up (adverb) + on (preposition)

Example Sentences

Upon boarding the flight from London Heathrow, the women discovered a stranger in one of the seats they believed they had booked - professional wrestler DeReiss Gordon, known in the ring as Man Like DeReiss.

From BBC • Apr. 30, 2026

Upon entering the home, guests are greeted with an expansive living room complete with soaring ceilings and “oversized picture windows.”

From MarketWatch • Apr. 28, 2026

Upon my return on Weekend 2, it doesn’t take much for a fellow journalist friend and me to fall out of Coachella’s orbit of constant documentation.

From Los Angeles Times • Apr. 26, 2026

Upon a Termination Event, Party A will pay Party B a tax-free cash distributive award based on the length of the marriage, equal to $100,000 per full year of marriage.

From The Wall Street Journal • Apr. 23, 2026

Upon this occasion my father said, with an expression of unbounded wonder, “My dearest Victor, what infatuation is this? My dear son, I entreat you never to make such an assertion again.”

From "Frankenstein" by Mary Shelley