Nikka is always running around the office.
My kid completely recovered from the traffic accident and now he's just running, full of energy.
After Koichi shot the bee hive, we ran around for nearly ten minutes trying to escape from all the bees.
You've seen the words 走る (to run) and 回る (to revolve). So, when you're running and revolving while you're doing it, you're running in circles. So, the verb form of that is to run around.
The readings are those like the words 走る and 回る. Make sure you know those words from before and apply that knowledge to read this word as well.