Borrowed from Italian certo.
ċertu (invariable)
ċertu (feminine singular ċerta, plural ċerti)
- a certain (named but not previously mentioned)
2022, Alfred Massa, Il-Ħarba, Horizons, →ISBN, page 7:Il-perċimes kien ċertu Rabbi Jacob u martu Rut.- The ringleaders were a certain Rabbi Jacob and his wife Rut.