noun A container consisting of one or more cells, in which chemical energy is converted into electricity and used as a source of power. (battery power) A fortified emplacement for heavy guns. A set of units of equipment, typically when connected together. (a battery of equipment to monitor blood pressure) The crime or tort of unconsented physical contact with another person, even where the contact is not violent but merely menacing or offensive. The pitcher and the catcher in a game, considered as a unit.