The quality or state of being the best; superiority or excellence.
From Middle English 'best' (superlative of 'good') plus the suffix '-ness' (indicating a state or quality). The suffix '-ness' comes from Old English and creates abstract nouns from adjectives.
This word is rarely used in modern English, but it shows how English speakers can stack suffixes to create new words—we could theoretically say 'bestness' just as easily as 'goodness,' which reveals how flexible and creative language can be.
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