The word "nurture" is already a noun. It means the process of caring for and encouraging the growth or development of someone or something.

If you're looking for a related noun, you could consider these options:

* Nurturer: A person who nurtures.

* Nurturing: The act of nurturing.

* Nurturance: The quality of being nurturing.

It's important to remember that nurture is a verb as well, meaning to care for and help grow.