The quality of being dull, bleak, depressing, or lacking in interest or color.
From 'dreary' + '-ness'. This is the standard noun form expressing the abstract quality of being dreary, formed using the productive '-ness' suffix that has been part of English since Anglo-Saxon times.
The 'drear-' root is actually connected to Old English words meaning 'blood' and 'gore'—so the original 'drearisome' feeling was about something literally grim and bloody, not just boring!
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