What is the adjective for maternal?

The adjective for "maternal" is maternal itself. It is already an adjective, meaning "relating to or characteristic of a mother."

However, depending on the context, you might use synonyms like:

* Motherly

* Mothering

* Nurturing

* Protective

* Caring

* Loving

* Tender

* Feminine (in some contexts)

The best choice will depend on the specific meaning you want to convey.