Adjective : a conscientious judge. ,conscientious application to the work at hand.    From Dictionary.com. 

Indeed, if we must adjudge to French journalists the palm for gracefulness and sprightliness, we cannot withhold it from them for unconscientiousness.    From Wordnik.com.  [Frederic Chopin as a Man and Musician]

An island is fine enough, in all conscience or piratic unconscientiousness, but an island in a river sounds like the beginning of the greatest adventure story on earth.    From Wordnik.com.  [Alarms and Discursions] Reference

The nervous unconscientiousness of Duthil, threatened with denunciation, was seen to revive; so, too, the anxious anger of the Baron, who was meditating how he might possibly manage to content Silviane.    From Wordnik.com.  [The Three Cities Trilogy: Paris, Volume 1] Reference

Nor during those years of youthful wanderings, does he ever seem, except upon one memorable occasion, to have been made to suffer from the unconscientiousness, the harshness, the infidelity, the indifference of the men and women whom he met, any more than in his boyhood he had suffered from the severity of his masters, the brutality of his tutor-servants, or the ill-nature of his fellow pupils.    From Wordnik.com.  [The Countess of Albany] Reference

“therefore” that I detect the unconscientiousness of this bird.    From Wordnik.com.  [A Tangled Tale] Reference