The research I've read generally lists two categories: domestic abuse, and domestic violence.
Violence being self explanatory, and abuse being what Mojo mentioned; emotional blackmail, withholding funds from a partner when they try to leave etc.
Domestic abuse is rightfully included in statistics. It can ruin a person's life just as much as domestic violence.
Different states and legal jurisdictions have different terms and slightly varied definitions, which adds to confusion.
In Victoria, family violence is the preferred term under law.
http://www6.austlii.edu.au/cgi-bin/viewdoc/au/legis/vic/consol_act/fvpa2008283/s5.html
No matter what term is used, if you are seeing stats, especially ones that are high (e.g. 1 in 3) it is almost certainly using the above, all encompassing definition, or very similar.
Ive read hundreds of peer reviewed studies on the topic and its pretty consistent in that regard. Always have to check the definitions and notes of what the stats are made up of, because they aren't always put front and centre.
Anyway, this isn't the thread for this. Sorry mods.
Edit: I'm not trying to diminish or disparage the seriousness of family violence. It is all abhorrent.