When you’re out hiking in the wilderness, you may have to ford a river if there’s no bridge. Roll up your pant legs because you'll have to wade through the water at a shallow point.
The verb ford describes crossing a body of water on foot at a shallow point or driving across it in a vehicle. The idea is that you’re not using a bridge or a boat to cross the water. Ford also has a noun form, meaning a shallow point in a river or stream. So if you ever have to ford a river, make sure you cross at the ford — the shallow point — or you could get very wet.