Unlawful, intentional causing of serious bodily injury with or without a deadly weapon, or unlawful, intentional attempting or threatening of serious bodily injury or death with a deadly or dangerous weapon. (http://www.ovc.gov/library/glossary.html)

Pertaining to data collected by the Bureau of Justice Statistics: An attack or attempted attack with a weapon, regardless of whether an injury occurred, and an attack without a weapon when serious injury results. With injury: an attack without a weapon when serious injury results or an attack with a weapon involving any injury. Serious injury includes broken bones, lost teeth, internal injuries, loss of consciousness, and any unspecified injury requiring two or more days of hospitalization. Threatened with a weapon: threat or attempted attack by an offender armed with a gun, knife, or other object used as a weapon that does not result in victim injury. (https://www.bjs.gov/index.cfm?ty=tda)