Legal Dictionary


Definition of omission


    Originally from Latin, omittere (“to send”). Post-classical Latin introduced the term omission; from the past participial stem of omittere, omiss- and the suffix -ion. This word was taken into Middle French and subsequently Anglo-Norman which heavily influenced the English language.


omission (plural omissions)

  1. The act of omitting.
  2. The act of neglecting to perform an action one has an obligation to do.
  3. Something deleted or left out.
  4. Something not done or neglected.
  5. (grammar) The shortening of a word or phrase, using an apostrophe ( ' ) to replace the missing letters, often used to approximate the sound of speech or a specific dialect.

Further reading

In the criminal law, an omission, or failure to act, will constitute an actus reus (Latin for "guilty act") and give rise to liability only when the law imposes a duty to act and the defendant is in breach of that duty.


In the criminal law, at common law, there was no general duty of care owed to fellow citizens. The traditional view was encapsulated in the example of watching a person drown in shallow water and making no rescue effort, where commentators borrowed the line, "Thou shalt not kill but needst not strive, officiously, to keep another alive." (Arthur Hugh Clough (1819-1861)) in support of the proposition that the failure to act does not attract criminal liability. Nevertheless, such failures might be morally indefensible and so both legislatures and the courts have imposed liability when the failure to act is sufficiently blameworthy to justify criminalisation. Some statutes therefore explicitly state that the actus reus consists of any relevant "act or omission", or use a word that may include both. Hence, the word "cause" may be both positive in the sense that the accused proactively injured the victim and negative in that the accused intentionally failed to act knowing that this failure would cause the relevant injury. In the courts, the trend has been to use objective tests to determine whether, in circumstances where there would have been no risk to the accused's health or well-being, the accused should have taken action to prevent a foreseeable injury being sustained by a particular victim or one from a class of potential victims.

So, returning to the drowning example, the accused would be liable if the victim was a child in a pool with a water depth of six inches, or there was a floatation device nearby that could easily be thrown to the victim, or the accused was carrying a mobile phone that could be used to summon help. However, the law will never penalise someone for not jumping into a raging torrent of water, i.e. the law does not require the potential saver to risk drowning even though the individual might be a lifeguard paid to patrol the given beach, river or pool. No matter what the terms of employment, an employee can never be required to do more than what is reasonable in all the circumstances. In R v Dytham (1979) QB 722 an on-duty police officer stood and watched a man beaten to death outside a nightclub. He then left without calling for assistance or summoning an ambulance. He was convicted of the common law offence of wilful misconduct in public office. Widgery CJ said:

    The allegation was not one of mere non-feasance, but of deliberate failure and wilful neglect. This involves an element of culpability which is not restricted to corruption or dishonesty, but which must be of such a degree that the misconduct impugned is calculated to injure the public interest so as to call for condemnation and punishment.

In the Attorney General's Reference (No 3 of 2003) (2004) EWCA Crim 868 police officers arrested a man with head injuries for a breach of the peace because of his abusive and aggressive behaviour towards the hospital staff who were trying to treat him. He later stopped breathing in the police station and all attempts at resuscitation failed. Five police officers, who were involved in the care of A at the time of his death, were charged with manslaughter by gross negligence and misconduct in a public office. It was held that the latter offence required that a public officer was acting as such, that he wilfully neglected to perform his duty and/or wilfully misconducted himself in a way which amounted to an abuse of the public's trust in the office holder, without reasonable excuse or justification; that whether the misconduct was of a sufficiently serious nature would depend upon the responsibilities of the office and the office holder, the importance of the public objects which they served, the nature and extent of the departure from those responsibilities and the seriousness of the consequences which might follow from the misconduct; that to establish the mens rea (Latin for "guilty mind") of the offence, it had to be proved that the office holder was aware of the duty to act or was subjectively reckless as to the existence of the duty; that the test of recklessness applied both to the question whether in particular circumstances a duty arose at all and to the conduct of the defendant if it did arise; and that the subjective test applied both to reckless indifference to the legality of the act or omission and in relation to the consequences of the act or omission.


  1. Wiktionary. Published under the Creative Commons Attribution/Share-Alike License.


1.     lex fori
2.     landed property
3.     lex situs
4.     respondent
5.     default judgment
6.     tort law
7.     living will
8.     lex causae
9.     law
10.     salacious