Where does “fontana” come from?

fontana (Medieval Latin) comes from Latin fontānus, from Latin fons, from Latin fontis — genitive singular of fōns.

Ancestry of “fontana”, step by step

Step	Language	Word	Meaning
1	Latin	fontānus	bearing a relation to the spring or source
2	Latin	fons	a spring, a fountain; fresh water, spring water;...
3	Latin	fontis	genitive singular of fōns