ouch

Etymology 1

Uncertain. Some sources say the interjection is attested since 1838 (and specifically in American English) and derives ultimately from German autsch, perhaps specifically via Pennsylvania German outch (“cry of pain”), as early attestations of the interjection are from Pennsylvania. However, others say the interjection is a "mere" or "natural" exclamation attested since the mid 1600s, and the 1933 OED cites one instance of a verb "ouch" in 1654, "Sancho Pancas Runs Ouching round the mountaine like a ranck-Asse".

intj

1. An expression of one's own physical pain.
   Ouch! You stepped on my toe! That hurt!
2. An expression in sympathy at another's pain.
   Ouch! Her sunburn looks awful.
3. A reply to an insult seen as savage (frequently one that is tongue-in-cheek or joking).
   Ouch. How could you say that?
4. An expression of disappointment.
   Ouch, I really wanted to do that.
5. (slang) Expressing surprise at the high price of something.
   Ouch, one hundred thousand dollars for a car! I could never afford that!

Etymology 2

Variant forms.

noun

1. Alternative form of ouche