The quality or state of being circular in shape, form, or nature.
From 'circular' plus '-ness,' a suffix from Old English '-nes' meaning 'state or quality of.' The '-ness' suffix is one of English's most productive noun-forming tools.
While 'circularity' and 'circularness' mean nearly the same thing, 'circularity' sounds more technical and philosophical, while 'circularness' feels more physical and concrete—showing how English lets us pick different emotional flavors of meaning.
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