Where does “карнавальный” come from?

карнавальный (Russian) comes from Russian карнава́л, from French carnaval, from Italian carnevale, from Latin carnem levāre.

карнавальный (Russian): carnival

Definitions

Step	Language	Word	Meaning
1	Russian	карнава́л	—
2	French	carnaval	The carnival, last festive occasion before Lent,...
3	Italian	carnevale	carnival; festival in the week before Lent
4	Latin	carnem levāre	—

карнавальный — Etymology, Origin & Word History | Etymology Explorer