Etymology: Latin homicidium, from homo- human being + caedere- to cut, kill

Homicide refers to the act of killing another human being. Reportedly, it can also describe a person who has committed such an act, though this use is rare in modern English. Although homicide does not define an illegal act necessarily, reportedly some jurisdictions use the word to indicate the unlawful killing of a person.

A Nolo Press glossary definition claims the legal definition of homicide involves, "The killing of one human being by the act or omission of another." A homicide defines any killing of one human being by another, criminal or otherwise. "Homicide is considered noncriminal in a number of situations, including deaths as the result of war and putting someone to death by the valid sentence of a court." Click Nolo Press's link for to see further definition of the term.

 Homicidal crimes

According to U.S. Legal, the law typically considers criminal homicide, or murder, a malum in se immorality, and every legal system contains some form of prohibition or regulation of criminal homicide.

Homicidal crimes include:

• murder/murder in English law
  • Felony murder
  • Capital murder
• manslaughter/manslaughter in English law
  • voluntary manslaughter
  • involuntary manslaughter
  • Intoxication manslaughter
  • Death by dangerous driving
  • reckless manslaughter
• Criminal Homicide
  • culpable homicide (in Scots law)
  • negligent homicide (in some criminal jurisdictions)
  • Criminally negligent homicide

Many forms of 'homicide' have their own term based on the person being killed.

• infanticide - Killing of an infant
• fratricide - Killing of one's brother; in a military context, killing of a friendly combatant
• sororicide - Killing of one's sister
• parricide - Killing of one's parents
• patricide - Killing of one's father
• matricide - Killing of one's mother
• mariticide - Killing of one's spouse
• uxoricide - Killing of one's wife
• filicide - Killing of one's child
• regicide - Killing of a monarch.
• genocide - Killing of a race
• suicide - Killing of oneself

 Non-criminal homicide

Homicides do not always involve a crime. Sometimes the law allows homicide either through certain defenses to criminal charges, or through exceptions or circumstances, e.g. state executions. Some legal homicides include:

• Justifiable homicide
• Capital punishment
• War