marginal cost vs differential cost

marginal cost and differential cost both are nouns.

Word	Noun	Adjective	Verb	Adverb
marginal cost	Yes	No	No	No
differential cost	Yes	No	No	No

As nouns, marginal cost and differential cost are synonyms defined as:

marginal cost and differential cost: the increase or decrease in costs as a result of one more or one less unit of output

Other synonyms of marginal cost include incremental cost.

marginal cost (noun)	differential cost (noun)
the increase or decrease in costs as a result of one more or one less unit of output	the increase or decrease in costs as a result of one more or one less unit of output