negligence
/ˈnɛɡlɪdʒ(ə)ns/

noun

failure to take proper care over something.
"his injury was due to the negligence of his employers"
Similar:
carelessness
lack of care
dereliction of duty
non-performance of duty
non-fulfilment of duty
remissness
neglectfulness
neglect
laxity
laxness
irresponsibility
inattention
inattentiveness
heedlessness
thoughtlessness
unmindfulness
forgetfulness
slackness
sloppiness
contributory negligence
culpa
barratry
delinquency
disregardfulness
inadvertence
inadvertency
oscitation
Opposite:
conscientiousness
attention to duty
LAW
breach of a duty of care which results in damage.