It's up in the air

http://cafe.naver.com/culcom/7529

(to be) up in the air - not yet determined; uncertain

ex1) It might rain later, so our plans for the picnic are up in the air. 

        이따가 비가 올지도 몰라, 그래서 소풍계획은 미정이다.

ex2) Our trip to Vancouver is up in the air. We aren't sure we'll get our visas in time.

        캐나다 여행은 미정이다. 우리 바지가 제때 나올지 확실하지 않다.

A: Are you going to the U.S next week?

B: No, the plans have been changed.

A: I thought it was all set.

B: So did I, but *something came up.

A: Any idea of when you will be going?

B: No, everything is up in the air. 

A: 너 다음주에 미국가니?

B: 아니, 계획이 변경됐어.

A: 모든게 다 준비된줄 알았는데.

B: 그랬지. 하지만 일이 생겼어.

A: 언제 가게 되는 줄은 알아?

B: 아니, 모든게 미정이야.

I'm sorry I won't be able to make it this time. Something came up!

미안한데, 이번 약속 취소해야 할 것 같아. 무슨일이 생겼어. 이런 뜻이죠.

:Freely available, ready to be taken.

ex1) After Mr. Yoon passed away, no one could find his will, so his estate is up for grabs. 

ex2) I don't want my sandwich --it's up for grabs, if anyone wants it. 

up for grabs도 up in the air와 비슷한 의미로 보시면 되요

그러면 왜 up for grabs이 그런 의미였을까 보면, 

When you 'grab' something, you reach for it very quickly. 

When something is up for grabs, it is out in the open waitng to be grabbed by whoever wants it. 

Do you have any plans on your wedding anniversary?

Mine is coming soon. It falls on 20th of June. It's up in the air. We might eat out and have a fun time if my baby boy Robin sits tight while having dinner. 

SDA: I thought about going with them, but something came up.