1. substance; true form; true character
もしかして仮面が本体なの?Wait, could the mask be your true form?
2. main part; main unit; body (of a machine)
本体は攻撃手段を持たない。The main unit has no means of attack.
3. object of worship (at a shrine, temple, etc.)
4. noumenon
5. base price; pre-tax price