An ungrounded conductor is commonly referred to as the ______ conductor.

The term commonly used to refer to an ungrounded conductor is "hot." In electrical systems, a hot conductor carries the electrical current from the power source to the load. It is energized and is not connected to the ground, which distinguishes it from ground and neutral conductors.

The ground conductor typically serves as a safety path for electrical current in case of a fault, while the neutral conductor is intended to carry current back to the source, completing the circuit. Since the question specifies an ungrounded conductor, it focuses solely on those that are energized and not connected to ground, making "hot" the correct terminology in this context.