Define referendum.

A referendum is accurately defined as a process by which legislative actions are voted on by the public before implementation. This procedure allows voters to directly participate in decision-making regarding specific proposed laws or amendments to existing laws. The hallmark of a referendum is its democratic nature, as it ensures that the public has a direct voice in shaping legislation that affects them, rather than solely relying on elected representatives to make those decisions.

In contrast, the other options do not capture the essence of a referendum. Proposing new laws without public input does not involve voter participation. Evaluating previous legislative decisions pertains more to accountability and oversight rather than the active participation in law-making that a referendum implies. Additionally, while a technique for amending the Constitution can involve public voting, it is a more specific procedure that does not encompass the broader scope of what a referendum covers.