I don't know what that means, but it's what it says on Wikipedia — there was a flaw and an error that meant that there was a certain probability that the result of the calculation would be an error, and the probability was one out of every 360 billion calculations.
Nu știu ce înseamnă asta, așa scrie în Wikipedia — era o greșeală ce dădea eroare, însemnând că exista o anumită probabilitate că rezultatul calculului ar fi incorect, iar probabilitatea era de 1 la 360 de miliarde de calcule.