something that you say to someone who disagrees with you in order to threaten them and offer to fight them.
'That's my beer you're drinking.' 'Do you want to make something of it?'
Do you want to make something of it?
A threat to fight or argue about something, usually something minor or easy to overlook. A: "Yeah? Do you want to make something of it?" B: "No, I'm sorry, I simply wasn't thinking when I said that about your marriage. That's all."