Unpleasant or ugly to look at; not attractive.
Prefix 'un-' (not) plus 'sightly' (from Old English 'gesihth,' visible/pleasing to sight). Compound formed in Middle English.
Beauty standards have changed completely over centuries—what Victorians found 'unsightly' (pale skin was beautiful, tan meant you worked outside), we might find beautiful now, which shows how much our eyes learn from culture.
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