Too close to call is an idiomatic expression that refers to a situation in which a decision or outcome is uncertain. It is often used in politics, sports, or any other situation where the outcome is not clear. There are many synonyms that can be used to express the same idea, such as undecided, uncertain, neck and neck, too close to predict, too close to choose, balanced on a knife-edge, down to the wire, and too close to be conclusive. These synonyms are all used to describe the same type of situation, where the outcome is still uncertain and could go either way.