The quality or state of being evident; the degree to which something is clear, obvious, or easily seen.
From 'evident' (clearly seen or understood) plus the suffix '-ness' (creating abstract nouns for qualities or states), which has been used in English since Old English to form nouns from adjectives.
The '-ness' suffix is one of the most ancient and productive tools in English—nearly any adjective can theoretically become a noun of quality by adding '-ness,' which is why we can create new words like 'awkwardness' or 'interestingness' instantly.
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