The British Idiom – Upset the apple cart
Definition of Upset the apple cart
To upset the apple cart is to ruin something or upset some previously made plans.
Examples of Usage of Upset the apple cart
Business was brisk until a competitor moved in next door and upset the apple cart by undercutting prices. The Americans were the superpower in the Pacific until the Japanese upset the apple cart by destroying part of their main fleet at Pearl Harbor.
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