* Plastri: This translates to "patch" in the sense of a piece of material used to cover a hole or wound.
* Darn: This translates to "patch" in the sense of a piece of cloth used to repair a tear in fabric.
* Cyfnewid: This translates to "patch" in the sense of a temporary fix or a workaround.
* Cyfnod: This translates to "patch" in the sense of a short period of time.
It's important to consider the context to choose the most accurate translation.
For example, if you're talking about a patch of grass, you might use gwely llysiau (garden bed).
If you can provide more context, I can help you find the most appropriate Welsh word.