Something that cannot be explained or understood; a mystery.
From the prefix 'un-' (not) combined with 'explainable,' which comes from Latin 'explanare' meaning 'to flatten out.' The modern word suggests something that resists being 'laid flat' or made clear.
We keep discovering that supposedly 'unexplainable' things (like placebo effects or why cats purr) actually have science behind them, so maybe the word should really mean 'not yet explained'—which is humbler and more scientifically honest.
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