What does BATTERY mean?

noun

1. group of guns or missile launchers operated together at one place
2. a device that produces electricity; may have several primary or secondary cells arranged in parallel or series
3. a collection of related things intended for use together“took a battery of achievement tests”
4. a unit composed of the pitcher and catcher
5. a series of stamps operated in one mortar for crushing ores
6. the heavy fire of artillery to saturate an area rather than hit a specific target“they laid down a barrage in front of the advancing troops”
7. an assault in which the assailant makes physical contact