The quality or state of being complimental; the nature of expressing or relating to compliments.
From complimental plus the noun-forming suffix -ness (from Old English -nes). This stacks multiple affixes on the Latin root compliment to create an abstract noun.
This word is theoretically perfect but practically invisible—it's what's called a 'morphologically impossible word,' one that follows all the rules of English word formation yet feels unnatural and clunky enough that speakers avoid it entirely.
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