Direct translation: cross (The cross of Christ)
It is a word used to assure someone that you are telling the truth or being serious.
Let's have a clean debate, you insult me I will block you and when we meet in the streets I will deal with you nicely.
Not a threat, I will sort you out nicely. Sefapano.
— Monsieur Ponto (@monsieurponto) April 11, 2020