wattmeter
/ˈwɒtmɛtər/Definitions
1. noun
An instrument used for measuring the power or energy consumption of an electrical device or circuit, typically in watts.
“The engineer used a wattmeter to check the energy efficiency of the new motor.”
2. noun
A device used in electrical power measurement, often in the form of a dial or digital display.
“The wattmeter on my power strip shows that my laptop is using a lot of power.”