Either looking down at something from above, or failing to notice something, or choosing to ignore a wrongdoing.
From 'over' + 'look,' a Germanic combination. The 'failing to notice' meaning developed around the 1600s from the idea of one's gaze passing over something without stopping; the 'forgive/ignore' meaning emerged by the 1700s.
The word 'overlooking' has opposite meanings depending on context (a window overlooking the valley = seeing from above; overlooking a mistake = ignoring) — linguists call this 'auto-antonymy,' and it reveals how perspective literally shapes meaning: the same action of 'not focusing on something' means different things depending on whether you're physically elevated or morally positioned above.
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