Where does “dulco” come from?

dulco (Latin) comes from Latin dulcis, from Proto-Indo-European dl̥kú- — sweet.

Ancestry of “dulco”, step by step

Step	Language	Word	Meaning
1	Latin	dulcis	sweet; sweet-smelling, sweet-scented, fragrant;...
2	Proto-Indo-European	dl̥kú-	sweet

dulco — Etymology, Origin & Word History | Etymology Explorer