"Holed up" is an expression that we often use to describe someone or something that is hiding or stuck in a certain place. However, there are plenty of alternative words that can be used to convey the same meaning. Some excellent synonyms for "holed up" include sequestered, confined, isolated, trapped, barricaded, and ensconced. Each of these words provides a slightly different shade to the meaning, depending on the context. For example, "sequestered" implies that the person is intentionally staying away from others, while "confined" indicates a lack of freedom. By using these alternative words, you can add variety and nuance to your writing, making it more engaging and interesting to your readers.