In a way that shows no care for danger or consequences; acting without thinking about risks or harm.
From 'reckless' (from Old English 'recceleas,' meaning careless), with the adverb suffix '-ly.' The word has meant 'not caring about consequences' since before 1000 CE.
The prefix 'reck' in 'reckless' comes from an old English verb meaning 'to care' or 'to heed'—so 'reckless' literally means 'not heeding,' which is why it describes someone ignoring obvious dangers!
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