Fills up with so much liquid or material that it spills over the top, or has an excessive amount.
From Old English 'over-' (beyond) + 'flowan' (to flow). The compound literally describes water flowing beyond its boundaries, metaphorically extended to emotional or quantitative excess.
In data science, 'integer overflow' is a critical bug where numbers get so large they wrap around to negative—computers literally overflow and break, which is why some websites crashed on January 19, 2038.
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