rotunda

noun

A circular building, especially one with a dome.

A large area with a high ceiling, as in a hotel lobby.

A large round room.

A round building, especially one with a dome; any building that is round both outside and inside. The most celebrated edifice of this kind is the Pantheon at Rome. See cuts under octastyle and pantheon.

A circular hall in a large building, generally surmounted by a dome.