the period preceding a notable event

it is going to be a busy run-up to Christmas

an act of running briefly to gain momentum before performing a jump in athletics, bowling in cricket, etc.

high jumper Steve Smith will use his shortened five-stride run-up

the bowler started his run-up

a low approach shot that bounces and runs forward

an act of running an engine or turbine to prepare it for use or to test it

other than for the first flight of the day, engine run-ups are not deemed necessary

a marked rise in the value or level of something

a sharp run-up of land and stock prices