To clock up is to reach a total of miles, hours or wins. Clock up the miles.
It suggests accumulation over time rather than any single achievement. The clock in it is a milometer, which is exactly what does the counting.
1phraseclock upTo reach a total of miles, hours or wins.
“The van would clock up thirty thousand miles a year.”
clock up is a phrase.
Practised in Phrasal Verbs