noun
walnut
Refers to the walnut tree or its nut, especially the common walnut (Juglans regia).
くるみを割って中身を取り出す。
Crack open a walnut and take out the kernel.
このパンにはくるみがたくさん入っている。
This bread has a lot of walnuts in it.
The origin is uncertain; possibly related to くるむ (to wrap) due to the shell enclosing the nut, but this is speculative.