There are no wrong answers, only your opinions 🙂
Personally, I think an anti-hero is a bad guy that does good things. He might cheat on his wife, steal, gamble, etc, but when it “matters,” he ends up on the side of what’s good.
Han Solo is an example that comes to mind.
Of course there are wrong answers, otherwise the term has no meaning.
To me, an anti-hero is a character in a story who does not try to be a hero, and is not motivated by a heroic drive, but rather is selfish, and maybe stumbles upon doing the right thing in the end.
Thomas Covenant the Unbeliever is an example of this.