year-and-a-day rule n: a common-law rule that relieves a defendant of responsibility for homicide if the victim lives for more than one year and one day after being injured NOTE: The year-and-a-day rule, which dates from at least 1278, is frequently criticized as anachronistic since modern medicine makes pinpointing cause of death easier than it was formerly. However, the rule still exists or is reflected in the law of some jurisdictions.
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.