We've all seen a few of these "holed" coins over the years. The size and placement of the hole in this coin looks like it was used as a "washer". The discoloration suggests it was used in a wet environment (possibly plumbing). If the hole were smaller and closer to the rim, I'd say it was a piece of jewelry. If the hole were jagged or uneven, I would say it was used for target practice, or maybe just a bored kid hit it with a hammer and nail. But nothing about the hole looks like a mint error. This is a good learning example for a new collector!