In a manner that is incurable or beyond treatment; hopelessly.
Adverbial form of 'cureless' formed by adding '-ly' (Old English 'lice'). The construction follows standard English patterns for converting adjectives to adverbs.
When adverbs get added to already-negative words like cureless, they pile sadness on top of sadness—'curelessly' sounds almost poetic in its bleakness.
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