地主 has two main noun senses. It refers to a 'landlord' in the sense of a landowner who rents out land — in the Chinese historical context, the term carries strong political and economic connotations from the pre-1949 landowning class, which English 'landlord' alone does not convey. It also means 'host' of an event or party, someone who receives guests. The modern host sense is neutral, while the landlord sense is historically loaded.