A problem that is difficult or impossible to solve because of incomplete, contradictory, and changing requirements that are often difficult to recognize. The use of term “wicked” as used here has come to denote resistance to resolution, rather than evil (Wikipedia). (Here is a link to an article on WICKED PROBLEMS.)
Wickedness isn’t a degree of difficulty. Wicked issues are different because traditional processes can’t resolve them, according to Horst W. J. Rittel and Melvin M. Webber, professors of design and urban planning at the University of California at Berkeley, who described them in a 1973 article in Policy Sciences magazine. A wicked problem has innumerable causes, is tough to describe, and doesn’t have a right answer.... Environmental degradation, terrorism, and poverty ... are classic examples of wicked problems.... Not only do conventional processes fail to tackle wicked problems, but they may exacerbate situations by generating undesirable consequences. Camillus HBR May 2008