Unique

google

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early 17th century: from French, from Latin unicus, from unus ‘one’.

wiktionary

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Borrowed from French unique.

etymonline

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unique (adj.)

c. 1600, "single, solitary," from French unique (16c.), from Latin unicus "only, single, sole, alone of its kind," from unus "one" (from PIE root *oi-no- "one, unique"). Meaning "forming the only one of its kind" is attested from 1610s; erroneous sense of "remarkable, uncommon" is attested from mid-19c. Related: Uniquely; uniqueness.