Noncomputable is a related term of undecidable.
As adjectives the difference between noncomputable and undecidable
is that
noncomputable is (mathematics|of a function) incapable of being computed by any deterministic algorithm in any finite amount of time while
undecidable is (mathematics|computing theory) incapable of being algorithmically decided in finite time for example, a set of strings is undecidable if it is impossible to program a computer (even one with infinite memory) to determine whether or not specified strings are included.