Not showing good judgment; foolish or imprudent.
From Old English 'unwis' (not knowing), combining 'un-' (not) with 'wise' (having knowledge); the word has meant 'foolish' for over a thousand years.
Wisdom and 'wise' both come from an ancient root meaning 'to see'—so being wise originally meant 'seeing clearly,' and being unwise meant having clouded judgment or missing what's obvious.
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