a person or thing that differentiates.
Computers. an electronic device whose output signal is proportional to the derivative of its input signal.
Electricity, Electronics. a transducer or circuit (differentiator circuit) whose output is proportional to the rate of change of the input signal.

Origin of differentiator

First recorded in 1885–90; differentiate + -or2
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019