From Longman Dictionary of Contemporary Englishhole up (also be holed up) phrasal verb informalHIDE/MAKE IT HARD TO FIND OR SEEto hide somewhere for a period of time in/with/at The gunmen are still holed up in the town. → hole→ See Verb table
Examples from the Corpus
hole up• The gang holed up in a cheap hotel for a few weeks.• The FBI believes that Richards is holed up on an estate in Colombia.• We were all planning to hole up till the trouble blew over. 