An "ouch" is an expression we use when we feel pain or discomfort.
When something hurts us, like stubbing our toe or getting a bug bite, we might say "ouch" out loud to let everyone know what's happening. We can also use it as a way to remind ourselves that something will hurt if we don't be careful - like saying "ouch, hot water!" when we turn on the tap too high. It's not just limited to physical pain either; sometimes people will say "ouch" when they're feeling embarrassed or stung by someone else's words.
An expression of one's own physical pain.
Example: Ouch! You stepped on my toe! That hurt!
