Impracticability
/ɪmˌpræktɪkəˈbɪləti/
Definition 1 of 1
Pro Tip 1/3Complexity Criterion
Use 'impracticability' when a task is too complex to complete, not just inconvenient or unpreferred. 
Despite the team's expertise, the impracticability of the algorithm's design halted progress.
Pro Tip 2/3Last Resort Term
'Impracticability' is often used as a last resort, after all alternatives have been considered and discarded. 
The committee declared the impracticability of the initiative only after extensive deliberation.
Pro Tip 3/3Not Context-Free
The word assumes understanding of the specific context in which a task or plan is unworkable. 
The impracticability of constructing a bridge here is due to the river's strong currents.