Noah Webster
Coefficient
COEFFICIENT, noun
1. That which unites in action with something else to produce the same effect.
2. In algebra, a number or known quantity put before letters, or quantities, known or unknown, and into which it is supposed to be multiplied; as in 3x and ax, 3 and a are the coefficients of x.
3. In fluxions, the coefficient of any generating term is the quantity which arises from the division of that term by the generated quantity.