Since I have lived in in the USA I have noted several different  words and colloquialisms that I didn't know about, until I arrived here. Here are a few examples;

Most of us know some of these words;

Trash/Garbage = Litter/Rubbish

Parking Lot = Car Park

Recess = Break/Playtime (at shool)

However, did you know ?  a Period = Full Stop

 an Eraser = a Rubber    a Rubber = a Sheath  and a Sheath = a Straight 'Shift' Dress

Fanny = Bottom

When people are pissed in the US it means they are angry or annoyed, in UK it means they are drunk!

Some of these words can get us into serious discussion subjects, on either side of the Atlantic, if not used correctly!

Here are a few more examples;

Pitcher = Jug 

Diaper = Nappy

Cot = Camp Bed

Gas(oline) = Petrol

Vacation = Holiday

Faucet = Tap.

Sledding = Sledging

Broil = Grill

Pocket Book =  Handbag or Purse

Sneakers = Trainers

Slides = Mules 

Cookie = Biscuit

Biscuit = Scone

Candy = Sweets

Do you know of any more?