The superlative form of 'blessed,' meaning the most blessed or most fortunate.
From Old English 'bletsian' plus the superlative suffix '-est.' Like 'blesseder,' this archaic superlative form was standard before modern English preferred 'most blessed.'
Before the 1600s, English speakers naturally said 'blessedest' for superlatives, but then '-est' fell out of favor for longer adjectives—watching how languages change shows us that even 'rules' are just habits that evolve.
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