Final answer:
A referendum is the term that best describes a vote by the electorate on a single political question referred to them for a direct decision.
Step-by-step explanation:
The term that best describes a vote by the electorate on a single political question referred to them for a direct decision is referendum. In a referendum, citizens are asked to confirm or repeal a decision made by the government, such as passing a law or amending the constitution. This form of direct democracy gives citizens the power to directly influence policy and laws in their state or country.