Adjective : an impracticable plan.    From Dictionary.com. 

There may be some who, in a disparaging tone, will at this stage of my confessions enter an accusation of impracticableness.    From Wordnik.com.  [The Confessions of a Beachcomber] Reference

No clerical magistrate had greater weight at sessions, or less of mischievous impracticableness in relation to worldly affairs.    From Wordnik.com.  [Daniel Deronda] Reference

I was even mad enough to think of venturing up the cavern again, but was restrained from the attempt by the certain impracticableness of it Then.    From Wordnik.com.  [Life And Adventures Of Peter Wilkins, Vol. I. (of II.)] Reference

Dolly, and with her; and Mrs. Copley, in spite of chewing the cud of mortification at Dolly's impracticableness, was beguiled into forgetting herself.    From Wordnik.com.  [The End of a Coil] Reference

It is better to bear the burden of impracticableness, than to stifle conviction and to pare away principle until it becomes more hollowness and triviality.    From Wordnik.com.  [On Compromise] Reference

Mrs. Falconer was too well aware of the impracticableness of her daughter's temper to tell her upon this occasion the whole truth, even if her own habits would have permitted her to be sincere.    From Wordnik.com.  [Tales and Novels — Volume 07] Reference

123, 124; its impracticableness, ii.    From Wordnik.com.  [Rousseau (Volume 1 and 2)] Reference