Definition
An instrument that measures and displays the total distance traveled by a vehicle or aircraft by counting the rotations of a wheel or shaft and converting that count into a distance reading.
Plain English
A device that keeps a running total of how far something has traveled.
Context Anchor
Seen in maintenance references when discussing instruments or equipment that record distance traveled, especially devices driven by wheel or shaft movement.
Derivation
From the Greek 'hodos' meaning 'road' or 'path', and 'metron' meaning 'measure'. So an odometer is literally a 'road measurer' — a device for measuring distance along a path.
Why Pilots Care
Knowing what an odometer records helps prevent confusing distance traveled with engine time, flight time, or speed.
Intuition Check
Do not assume an odometer measures time, speed, or engine use. It measures distance traveled.
Example Sentence 1
The mechanic checked the fuel truck's odometer to see how many miles it had logged since its last service.
Example Sentence 2
Ground support vehicles use an odometer to log total distance during ramp operations and towing.