IPA: /ˈwɛrəˌpɒn/
KK: /wɛrˈʌpɒn/
A word used to indicate that something happens immediately after another event or action.
The meeting ended, whereupon everyone left the room.
Whereupon is formed from "where" (from Old English "hwær", meaning at what place) and "upon" (from Old English "uppon", meaning on or upon). The word "whereupon" means at which place or point something occurs, often used to indicate a consequence or result following a previous statement.
Think of 'where' as asking about a place and 'upon' as indicating a position — together, they help you remember that 'whereupon' refers to a point in time or place where something happens.