The state or quality of being associated; the degree to which things are connected, related, or grouped together.
From 'associated' (past participle of 'associate') plus -ness, creating an abstract noun that expresses the quality of being in a state of association.
Words ending in -edness (like 'relatedness,' 'connectedness,' 'preparedness') are fascinating because they freeze a process into a state—they're describing the result or condition after something has happened.
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