eggs is eggs

A phrase used to describe something that is definitely going to happen. It might be a corruption of the phrase "x is x." Typically used in the phrase "(as) sure as eggs is eggs." Of course I'll be there, sure as eggs is eggs! As sure as eggs is eggs, Evelyn got the promotion—she is the boss's favorite, after all. The two brothers will be forever at each other's throats, as sure as eggs.