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1530s, "pertaining to the earliest period, primitive, ancient," from Middle French pristin or directly from Latin pristinus "former, early, original," from Old Latin pri "before" (see prime (adj.)). Meaning "unspoiled, untouched, pure" is from 1899 (implied in a use of pristinely) but according to OED 2nd ed. print still regarded as ignorant "by many educated speakers."