Batter is a flour mixture with liquid and other ingredients such as sugar, salt, egg, milk and leavening used for cooking.
Many batters are made by combining dry flour with liquids such as water, milk, or eggs.
Often a leavening agent such as baking powder is included to aerate and fluff up the batter as it cooks, or the mixture may be naturally fermented for this purpose as well as to add flavour.
The practice of beer battering is popular in Australia, New Zealand, the United States, Britain, Ireland, Germany, Iceland and Russia.
Tempura in Japan, pakoda and dosa in India, galapong in the Philippines, spoonbread in the US, and many other examples are all types of batters.