Doing (noun)

1. An action or activity, especially one that is ongoing or in progress.
2. A state of being active or engaged in something.
3. A result or outcome, particularly of an action or activity.

Origin:

From the middle english word doyng, meaning an action or activity.

Examples:

1. The doing of the project was difficult, but the result was worth it.
2. She enjoyed the doing of the task, even though it was tedious.
3. The doing of the experiment required a lot of precision.
4. I don't know what the doing of the plan will be like.
5. She was proud of the doing of her work.