1) a war in which parties within the same culture, society or nationality fight against each other for the control of political power.
2) a song by guns n roses
3) a slang term used to describe a food fight within one table at lunch or any other public place in which food is eaten.
EXAMPLES 3) Bill: Hey, don't be starting a civil war here!
Joe: We haven't had one in a long time.
1) Chris: Who won the Civil War?
John: I don't know, dude. Ask someone else.