Definition
The combination of two violent crimes: assault (the threat of violence) and battery (physical violence). This legal distinction exists only in jurisdictions that distinguish assault as threatened violence rather than actual violence.
How People Actually Use It
(Not to be confused with domestic violence,m since more often than not, domestic violence is single-handedly one-sided): when both partners in a relationship commit physical, mental, emotional and psychological violence and abuse against each other, usually following acrimonious arguments.
"IMHO Slava Voynov's recent case is double-barreled assault and battery, not domestic violence, since both he and his girlfriend required medical attention following the incident."
Source: Urban Dictionary