certeza
/θeɾˈteθa/ · B1 · noun · f
certainty
certeza = cierto (certain) + -eza (-ness): certain-ness
From Latin certus, sure, the same root as English certain. The suffix -eza turns adjectives into nouns, like belleza from bello. It is feminine: la certeza. A common phrase is con certeza, with certainty.