The word 'marginal' is associated to a slight difference between two quantities. So, when you say marginal benefit, this refers to the benefit you acquire with every additional unit you produce. This benefit can be measured in different ways, like additional utility or satisfaction. For example, for every additional unit produced, you acquire a marginal benefit of $1. In this case, the benefit is in terms of profit.
Thus, the answer is most likely: Another term for "Marginal Benefit" is "Marginal Utility."
