Plain English Meaning
A small electrical tester that can check voltage, current, or resistance, depending on which setting you select. One tool, several jobs.
Full Definition
A handheld electrical test instrument that measures multiple electrical quantities, typically voltage, current, and resistance, and displays the readings on either an analog needle scale or a digital screen.
Context Anchor
Seen during aircraft electrical troubleshooting, wiring checks, battery checks, and maintenance inspections.
Derivation
From 'multi-' (Latin multus, meaning 'many') plus 'meter' (Greek metron, meaning 'measure'). Literally a 'many-measure' device — one instrument that measures several different electrical values instead of needing a separate meter for each.
Why Pilots Care
Maintenance technicians rely on a multimeter to find faults in aircraft wiring, confirm bus voltages, and verify continuity in circuits before signing off work. A correct reading on the right setting can be the difference between catching a fault on the ground and discovering it in flight.
Analogy
A multimeter is like a basic health-check tool for an electrical system: it does not fix the problem by itself, but it helps show what is present, missing, or interrupted.
Example Sentence 1
The technician used a multimeter to check the voltage at the battery terminals before installing the new battery.
Example Sentence 2
To diagnose the avionics power issue, check the bus voltage with a multimeter set to DC volts.