The act of putting off or postponing something can be described as?

The act of putting off or postponing something is best described as "deferment." This term specifically refers to the action of delaying or rescheduling an event, task, or obligation to a later time. Deferment conveys a sense of intentionality in postponing, often to allow for more favorable conditions or to allocate resources effectively for a later date.

In contrast, the other terms do not relate to postponement. Expediting refers to the process of speeding up or facilitating a task, which is the opposite of postponing. Accelerating similarly implies an increase in speed or urgency in completing a task, again contradicting the idea of putting something off. Alleviating involves reducing the severity of a problem, rather than postponing an action or decision. Therefore, deferment is the most appropriate choice for describing the act of postponement.