The quality or condition of being butyrous; the state of resembling butter or having butter-like properties.
From butyrous + -ness (Old English suffix forming abstract nouns from adjectives). Creates an abstract noun describing the quality itself rather than the substance.
The -ness suffix is incredibly productive—you can add it to almost any adjective to create an abstract noun representing that quality, which is why English can express such subtle ideas through word combination.
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