Be holed up
Definition 1 of 1
Pro Tip 1/3Refuge During Trouble
Often means someone is avoiding trouble or hiding after doing something wrong. 
The smuggler was holed up in a cabin to evade the police.
Pro Tip 2/3Extended Periods
Implies staying in one place for a long time without leaving or being seen. 
He was holed up in his room all summer studying for exams.
Pro Tip 3/3Seeking Safety
Can indicate seeking protection from danger, like bad weather or a threat. 
During the hurricane, many people were holed up in shelters.