Definition: A milliampere (mA) is a unit of electric current equal to one thousandth (10⁻³) of an ampere. It is a subunit of the base unit, the ampere, in the International System of Units (SI).

History/origin: The ampere is named after French physicist André-Marie Ampère. The milliampere, as a decimal multiple of the ampere, was naturally derived as a smaller, more convenient unit for measuring smaller currents. Its usage grew with the development of electronics.

Current use: Milliamperes are commonly used to measure small currents in electronic circuits, portable devices, sensors, and other low-power applications. It is a practical unit for specifying the current requirements and capabilities of components and circuits.