The phrase "to fit out" means to equip, furnish or supply something with necessary items. It can refer to a process of preparing and equipping a space for its intended use by installing fixtures, furniture, and other equipment needed to make it functional. This could be done in the context of setting up an office, a home, a retail store, or any other type of space that requires customization according to specific needs. The phrase can also refer to outfitting someone with necessary items such as clothing, gear or tools for a particular purpose or activity.