The Collaborative International Dictionary of English v.0.48:

Ouch \Ouch\ (ouch), n. [OE. ouch, nouche (a nouch being taken
   for an ouch: cf. Adder), fr. OF. nusche, nosche, nousche,
   buckle, clasp, LL. nusca, fr. OHG. nusca, nuscha.]
   A socket or bezel holding a precious stone; hence, a jewel or
   ornament worn on the person.
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         A precious stone in a rich ouche.        --Sir T.
                                                  Elyot.
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         Your brooches, pearls, and ouches.       --Shak.
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