The quality of being exclusive; the state of being limited to a select few people or things, or the practice of excluding others.
From 'exclusive' (from Latin 'excludere') + '-ness' (a state or quality). The '-ness' suffix converts the adjective into an abstract noun.
Luxury brands deliberately market 'exclusiveness' as a feature—the value comes partly from the fact that not everyone can have it, so the word names something that's valuable specifically because it excludes most people.
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