- Not tractable; not able to be managed, controlled, governed or directed.
- 1972, Edsger W. Dijkstra, The Humble Programmer (EWD340):
- And I cannot but expect that this will repeatedly lead to the discovery that an initially intractable problem can be factored after all.
- (mathematics) (of a mathematical problem) Not able to be solved.
- (of a problem) Difficult to deal with, solve, or manage.
- (of a person) Stubborn; obstinate.
- (medicine) Difficult to treat (of a medical condition).
mathematics: not able to be solved
of a problem: difficult to deal with, solve, or manage
medicine: difficult to treat