Out of left field - Unrelated to the issue at hand, or whatever is being discussed. Katie made a really strange comment yesterday. It didn't have anything to do with what we were talking about. It was just so out of left field!

Out of my hands - Out of your control. It's out of my hands now.

There's nothing I can do to make changes to the project.

Out of order - No longer working or effective; in some contexts, unacceptable. Don't bother putting your money in that vending machine. It's out of order and won't give you a candy bar.

Out of the blue - Something that occurs unexpectedly and abruptly. That letter really came from out of the blue! I hadn't heard from her in years!

Out of the question - Not possible or acceptable. It's simply out of the question for him to buy that. He can't afford it.

Out of the woods - A difficult situation has improved or become easier to deal with. The most challenging part is over. The horrible time the Maxwell family has been going through might end soon, but they're not quite out of the woods yet.

Out of this world - Extraordinary.

The celebration was out of this world. It was extraordinary and something I'll never forget.

Out on the town - To go out and enjoy yourself.

They went out on the town last night, visiting a few nightclubs and just having fun.

Out to lunch - Confused or unaware of circumstances or reality, or perhaps absentminded.

I tried to talk to my professor this morning but he seemed very distracted. I've heard of professors being a little absentminded, but this guy is out to lunch!