Meaning of Weierstrass approximation theorem

Wei'erstrass approxima'tion the"orem

Pronunciation: [key]
— Math. Math.
  1. the theorem that for any continuous function on a closed interval, there is a polynomial such that the difference in values of the function and the polynomial at each point in the interval is less in absolute value than some positive number.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.