The quality or state of being disgusting; extreme repulsiveness.
From 'disgusting' (present participle form of disgust) plus '-ness'. This is the standard modern formation, preferred over 'disgustfulness' because '-ing' + '-ness' feels more natural in contemporary English.
Compare 'disgustingness' with 'disgustfulness'—modern English prefers the '-ing' form, showing how which suffixes feel natural shifts over time as languages evolve their style preferences.
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