Real Dictionary

run up
phrasal verb: If someone runs up bills or debts, they acquire them by buying a lot of things or borrowing money.

run up in American English
to raise, rise, make, or build rapidly
to sew rapidly

run up in British English
to amass or accumulate; incur
noun: an approach run by an athlete for a long jump, pole vault, etc

run-up
countable noun: In sport, a run-up is the run made by a player or athlete, for example before throwing a ball or a javelin, or before jumping.
singular noun: The run-up to an event is the period of time just before it.

run-up in American English
a preparatory period preceding an important event

run-up in British English
noun: the period of time just before an event