1. the quality or state of being circular in shape or form
2. the quality of being circular in logic or reasoning; the fallacy of using a conclusion to support its own premise
Usage: logic, philosophy

Examples

• The circularness of the planet makes it unique among celestial bodies.
• The architect praised the circularness of the dome's design.
• The argument suffered from circularness, as it assumed the very thing it tried to prove.
• The circularness of their logic made the debate go nowhere.
• We measured the circularness of the wheel to ensure it would roll smoothly.