A punt is a long, flat boat that's used for cruising or rowing on calm waters. You can rent one and take it out on a lake or river.
When people talk about punting, they often mean taking a relaxing ride on a punt, usually with a guide who rows you along. It's a popular tourist activity in places like England and France, where the boats are typically long and stable. If someone says they went punting over the weekend, it means they took a leisurely boat ride.
(nautical) A pontoon; a narrow shallow boat propelled by a pole.
