Nomihodai (飲み放題 nomihōdai?) is an "all-you-can-drink" option at some clubs, restaurants, nomiya-san (bars), and most karaoke establishments throughout Japan. The word hodai is often used in Japanese to mean "all-you-can", therefore tabehodai = all you can eat, and tsukaihodai = unrestricted use. While prices and menus vary, beer, wine, mixed drinks, and shochu based drinks are usually included. Sometimes a discount for off-peak hours can be found. This is a great way to have fun and not go broke, especially when out with friends for hours on end.
But be careful because at some nomihodai "last order" can be 15 minutes before your time has ended, and at some (specifically restaurants) a two-hour tabehodai can mean you expected to leave after two hours. If you are planning an event, specifically involving large amount of people and money, be sure to discuss what the terms are before hand with the establishment, or you may end up underfed, and unsatisfied.