"Dead certainties" is a phrase that refers to something that is absolutely certain to happen or be true. Synonyms for this phrase could include "foregone conclusions," "sure bets," "unalterable outcomes," "inevitable results," "guaranteed certainties," or "inevitable conclusions." These alternatives capture the sense of finality and conviction that the original phrase conveys. Whether we are talking about a sporting event, a legal verdict, or a scientific discovery, these synonyms help to express the idea of something being a fixed and conclusive fact that cannot be disputed or altered.