What Words Are Used In A Different Way Between Americans & the British?
Here, to kick things off are some that come to mind - with the US version first:
Pants = Trousers.
Panty Hose = Tights.
Gas = Petrol (or Diesel). (Gas to a Brit = Natural Gas that flows into the home. Why would Americans call a liquid a Gas)?
French Fries = Chips. (The British do use the term French Fries to describe the think sticks that the Americans eat but the Brits usually have 'Chips' - meaning the thicker fried potato 'fingers'). Do try & have Fish & Chips when in the UK.
Interstate or Freeway = Motorway. (A fast multi-lane long distance highway).
Railroad = Railway.
Condominium = Flat or Apartment block.
Sidewalk = Pavement.
Subway = Underground / Tube. (A subway in Britain is the term applied to an underground passage such as you might find taking pedestrians under a busy road. It would not be used as a term for underground trains but could be used to describe the passageways taking people to the platforms to catch such trains).