differentiant

from The Century Dictionary.

• Of or pertaining to a discontinuous variation, sport, mutation, or inherited change in the type of a race or species.
• noun In mathematics, a rational integral function of the coefficients of a binary quantic, of equal weight in all its terms in respect to either variable, subject to satisfy the condition
• noun where a, b, c, etc., multiplied by binomial coefficients, give the coefficients of the quantic, and where D is the differentiant.