Meaning of Tchebycheff polynomial

Tchebycheff' polyno"mial

Pronunciation: [key]
— Math. Math.
  1. a polynomial solution of the Tchebycheff equation, of the form T(x) = cos(ncosx), where n is an integer. Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.