陪客 is a separable verb (离合词) meaning 'to keep a guest company' or 'to entertain a guest'. It is used when you spend time with a visitor or client to make them feel welcome, often in social or business settings. The second sense in the source — 'service clients (of prostitutes)' — is a vulgar or specialized usage that is not appropriate for general learning and is omitted here. As a separable verb, you can insert measure words or other elements between 陪 and 客, e.g., 陪过几次客 ('kept guests company a few times').