The quality of being grim; a state characterized by seriousness, harshness, or forbidding appearance.
Grimly + -ness (noun suffix), from grim + -ly. Grim comes from Old Norse/Germanic roots meaning 'fierce, savage, stern.'
Grim starts from the same root as 'grin'—both go back to fierce facial expressions, but grim stayed scary while grin evolved into something happy, a fascinating reversal.
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