Meaning of jump discontinuity

jump' discontinu"ity

Pronunciation: [key]
— Math. Math.
  1. a discontinuity of a function at a point where the function has finite, but unequal, limits as the independent variable approaches the point from the left and from the right. Cf. jump (def. 60).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.