Berth has two main meanings:

1. A bed or sleeping place on a ship, train, or other vehicle. When sailors sleep on a ship, each one has their own berth, which is usually a narrow bed built into the wall. On an old-fashioned sleeper train, passengers might book a berth in a sleeping car, where they can lie down during a long overnight journey. These berths are compact and efficient, designed to fit into tight spaces while still giving travelers somewhere comfortable to rest.
2. A place where a ship docks at a harbor. When a cruise ship arrives at port, it pulls into its assigned berth, a specific spot along the dock where it can safely tie up. Harbor masters carefully manage berths because large ships need plenty of room and can't just dock anywhere. A ship's captain might radio ahead to request a berth, just like you might reserve a parking spot before a big event.

People also use the phrase “give it a wide berth,” which means to stay far away from something, like giving a wide berth to a grumpy dog or a difficult situation.