From hole + up. Attested from the 19th century.
hole up (third-person singular simple present holes up, present participle holing up, simple past and past participle holed up)
- (intransitive) To go into a hole, to shelter in a hole.
1998, John Whitaker and William Hamilton, Mammals of the Eastern United States, page 424:
In the Upper Peninsula of Michigan bears enter winter dens in October; in the South, later; even in Florida bears “hole up” during the coldest weather.
- (originally US, intransitive) To hide.
- The guerrillas holed up in a small cave.
- 2005, BBC News, Thursday, 27 January, 2005, 18:50 GMT:
- The battle ended a two-day siege of an apartment block, where the suspects were holed up.