main guest; guest of honor
Refers to the most important guest at a formal event such as a wedding, banquet, or ceremony.
結婚式の主賓としてスピーチを頼まれた。
I was asked to give a speech as the guest of honor at the wedding.
主賓が到着するまで、会を始められない。
We cannot start the event until the main guest arrives.
主賓 is the single most important guest of honor at an event, while 来賓 refers more broadly to any invited guests, often several of them.
Compound of 主 (main) and 賓 (guest). The kanji 賓 is a formal term for a guest, often used in ceremonial contexts.