US English | UK English | Meaning in US English | Meaning in UK English
------- | -------- | -------- | --------
Fall | Autumn | The season after summer | To drop, to tumble, to decrease
Fanny | Bottom/bum | A woman's buttocks | A handbag
Pants | Trousers | Undergarments worn on the lower body | Long pants (usually for men)
Rubber | Eraser | A material made from vulcanized latex | A condom
Mad | Angry | Extremely angry | Crazy, insane
Gas | Petrol | Natural gas used as fuel | Gasoline
Candy | Sweets | Confectionery | Confectionery
Trash | Rubbish | Garbage | Garbage
This is just a small sampling! There are many other words with slightly different meanings depending on which side of the Atlantic you're on. Keep in mind that these differences are mainly in informal usage and may not be strictly universal.
Let me know if you'd like to explore more of these linguistic curiosities!