Where does “слъньце” come from?

слъньце (Old Church Slavonic) comes from Proto-Slavic sъlnьce, from Proto-Balto-Slavic *súlˀnis, from Proto-Indo-European sóh₂wl̥ — sun.

слъньце (Old Church Slavonic): sun

Definitions

Step	Language	Word	Meaning
1	Proto-Slavic	sъlnьce	sun
2	Proto-Balto-Slavic	*súlˀnis	—
3	Proto-Indo-European	sóh₂wl̥	sun

слъньце — Etymology, Origin & Word History | Etymology Explorer