impracticality
noun /ɪmˌpræktɪˈkæləti/
  /ɪmˌpræktɪˈkæləti/
[uncountable, countable] (plural impracticalities)
- the fact of not being sensible or realistic; a thing that is not sensible or realistic- She explained to her superiors the impracticality of such a project.