David is out for lunch.
David出去吃午饭了。

be/go out for...
出去做...
Susan is out for shopping.
苏珊出门购物了。
Let's go out for a drink.
我们出去喝一杯吧。

A:Hello. Can I talk to David?
你好。能让David接电话吗？
B:One second, please. ( a few seconds later, the receiver comes back and says) Hello?
请稍等。（片刻后，接电话者返回并说）喂？
A:Yes.
请讲。
B:I'm sorry. David is out for lunch right now.
很抱歉，David出去吃午饭了。
A:Okay. I'm his wife. Could you tell him to call me back when he returns?
好的。我是他妻子。等他回来了能让他给我回个电话吗？
B:Sure.
当然。
A:Thanks. Please tell him to call my cell-phone number.
谢谢。请让他打给我的手机。
B:Ok, I will.
好的，我会的。
A:Thank you very much.
非常感谢。
B:No problem.
被客气。