Neglectfulness (6)
I believe the answer is:
laxity
'neglectfulness' is the definition.
(laxity is a kind of neglectfulness)
This is the entire clue.
(Other definitions for laxity that I've seen before include "Poor discipline, lack of authority" , "Carelessness or negligence" , "Slackness, absence of discipline" , "Lack of precision" , "Freedom" .)