The quality of being apparent or obvious; clarity or plainness. The degree to which something is evident or easy to see.
From 'apparent' + English suffix -ness (creating abstract nouns from adjectives). The -ness suffix is the most productive way to convert adjectives into abstract nouns in English. This is the modern standard form for the noun concept.
Compare 'apparentness,' 'apparency,' and 'apparence'—three ways to nominalize 'apparent' from different historical layers of English. The -ness form won because it's most productive and transparent to modern speakers.
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