To revert a series

(Alg.) to treat a series, as y = a + bx + cx2 + etc., where one variable y is expressed in powers of a second variable x, so as to find therefrom the second variable x, expressed in a series arranged in powers of y.

See also: Revert

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.