negligence

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The state or quality of being negligent.
• noun A negligent act or a failure to act.
• noun Failure to use the degree of care appropriate to the circumstances, resulting in an unintended injury to another.
• noun An act or omission showing such lack of care.

from The Century Dictionary.

• noun The fact or the character of being negligent or neglectful; deficiency in or lack of care, exactness, or application; the omitting to do, or a habit of omitting to do, things which ought to be done, or the doing of such things without sufficient attention and care; carelessness;. heedless disregard of some duty.
• noun Specifically, in law, the failure to exercise that degree of care which the law requires for the protection of those interests of other persons which may be injuriously affected by the want of such care.
• noun Lack of attention to niceties or conventionalities, especially of dress, manner, or style; disregard of appearances; easy indifference of manner.
• noun An act of neglectfulness; an instance of negligence or carelessness.
• noun Contempt; disregard; slight; neglect.
• noun A kind of wig in fashion for morning dress about the middle of the eighteenth century.
• noun Synonyms Heedlessness, inconsiderateness, thoughtlessness.
• noun 1 and Negligence, Neglect, Remissness, Inattention, Inadvertence, Oversight, Indifference. As contrasted with neglect, negligence generally expresses the habit or trait, and neglect the act. Inadvertence and oversight expressly mean that there was no intention of neglect; indifference lies back of action in the failure to care, such failure being generally blameworthy. Remissness is careless neglect of duty. Inattention is a failure. generally culpable, to bring the mind to the subject. See neglect, n. t, and negligent.

from the GNU version of the Collaborative International Dictionary of English.

• noun The quality or state of being negligent; lack of due diligence or care; omission of duty; habitual neglect; heedlessness.
• noun An act or instance of negligence or carelessness.
• noun (Law) The omission of the care usual under the circumstances, being convertible with the Roman culpa. A specialist is bound to higher skill and diligence in his specialty than one who is not a specialist, and liability for negligence varies acordingly.
• noun See under Contributory.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The state of being negligent.
• noun law, singular only The tort whereby a duty of reasonable care was breached, causing damage: any conduct short of intentional or reckless action that falls below the legal standard for preventing unreasonable injury.
• noun law, uncountable The breach of a duty of care: the failure to exercise a standard of care that a reasonable person would have in a similar situation.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun failure to act with the prudence that a reasonable person would exercise under the same circumstances
• noun the trait of neglecting responsibilities and lacking concern