Odometer, for one (5)
I believe the answer is:
gauge
'odometer for one' is the definition.
(I know that odometer is a type of meter)
This is all the clue.
(Other definitions for gauge that I've seen before include "Rail track width" , "Distance between the rails of a railway track" , "Measuring instrument" , "Measure against a standard" , "Meter" .)