Ouch is defined as a way to express pain.(interjection)
When someone steps on a piece of glass, their exclamation is an example of ouch.
See ouch in Webster's New World College Dictionary
Origin: echoic of natural cry
Origin: < ME (a n)ouche < OFr nousche < Frank *nuskja, brooch, akin to OHG nusca, a clasp < IE base *ned-, to twist together > net
See ouch in American Heritage Dictionary 4
Origin: Middle English ouche
Origin: , from Anglo-Norman (une) ouche
Origin: , alteration of (une) nouch, (a) brooch
Origin: , of Germanic origin; see ned- in Indo-European roots.
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