The quality or state of being cloggy; the tendency to clog or obstruct.
From 'cloggy' plus the noun-forming suffix '-ness,' which creates abstract nouns describing qualities and states. This follows one of English's most productive word-formation patterns.
The '-ness' suffix is so flexible that you can almost attach it to any adjective (blueness, silliness, clogginess) and native speakers will instantly understand you—it's one of English's most powerful tools for creating new words!
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