It's the Japanese word for sunlight, which is filtered through the leaves of the trees. In particular, it means the visible light rays. “Komorebi” is composed of several parts of the word: “Ko” means tree or trees. “More” means: something that comes through, something that shines through or seeps through. “Bi” means: sun or sunlight.
The word “Komorebi” reflects the romantic and emotional love of the Japanese for nature.