Meaning of Fourier transform

Fou'rier trans"form

Pronunciation: [key]
— Math. Math.
  1. a mapping of a function, as a signal, that is defined in one domain, as space or time, into another domain, as wavelength or frequency, where the function is represented in terms of sines and cosines.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.