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.

---

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

---

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).

---

Etymology

Origin of upon

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

Example Sentences

Captain Silva and defender John Stones will both leave upon the expiry of their contracts next month and they were presented with framed shirts by their manager.

From BBC • May 24, 2026

When your trust turns irrevocable upon your death, it likely cannot be modified or terminated without the permission of the grantor’s beneficiaries.

From MarketWatch • May 23, 2026

“Basically, I’m wondering if the reaction is over, or, or if upon stopping the cooling mechanism, if it would re-initiate itself.”

From Los Angeles Times • May 23, 2026

He never flinched, instead taking it upon himself to bring up prominent women with alopecia.

From Slate • May 23, 2026

They’ve attempted to bring disorder and destruction upon the puffin nation.

From "The Very, Very Far North" by Dan Bar-el