A mathematical problem is ill-posed if no solution exists, more than one solution exists, or the solution does not depend continuously on the problem's data. Ill-posedness concerns solutions to problems, whereas ill-defined concerns definitions or constructions that do not determine unique meanings or values.
Ill-Posed
See also
Ill-Defined, Well-Defined, Well-PosedExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Ill-Posed." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Ill-Posed.html