intractable
adj. C1 Advanced US //ˌɪnˈtɹæktəbəɫ// UK //ɪntɹˈæktəbəl// in·tractable
adj. describing a problem or situation that is very difficult to fix or control. It is often used for things that seem impossible to solve no matter how hard you try.
adj. refusing to be controlled, managed, or solved; resistant to treatment or correction. Often describes mathematical problems or medical conditions that defy standard solutions.
The doctors found the infection to be intractable.
The researchers struggled for years to find a cure for the intractable disease that had plagued the region.
Mathematicians often classify certain equations as intractable because they lack a general solution that can be applied across all possible variables.
From in- + tractable.