自家 is a colloquial or dialectal pronoun meaning 'oneself' or 'one's own', used in many northern Chinese dialects and in older literary Chinese. In standard Mandarin, the more common word is 自己 (zìjǐ), but 自家 carries a slightly more familiar or folksy tone, especially in spoken expressions or traditional idioms. As a pronoun, it can be used as subject, object, or as a possessive determiner (e.g. 自家的事 'one's own business').