1. In the United States, the temporary closing of a bank in the event that its obligations exceed its resources. 2. In the United Kingdom and Ireland, a public holiday on which the banks are closed. A bank holiday is generally not a major holiday such as Christmas Day (although, the banks are indeed closed on these holidays), but instead a day that would otherwise be a non-holiday. For example, the first Monday in May is considered a bank holiday, and banks along with many other businesses close for the day.