Lead-in to meter

ODO

Think of the device that tracks how far a car travels before its name.

The clue plays on the word "odometer," which is a device that measures distance traveled by a vehicle. "Meter" here refers to the measuring part of the word, while "lead-in" hints at the prefix that comes before it—"odo." It’s a straightforward prefix clue where "odo" is the starting piece of a familiar term.