sit tight

to SIT TIGHT  기다리다

When you're anxious, it might be best to SIT TIGHT. 

What does that mean?

Sit down and don't move. You don't have to do anything except wait .

Wait and be patient. Just wait and be patient.

I'll do it for you. I'll bringing to you. It will happen. Don't worry. Relax. Sit tight. 

Here is dialogue.

A : I sent you my application. Now what should I do? 

B : Just to sit tight. 

A : You'll contact me?  

B : Yes, we'll contact you within two weeks. 

A: 저기 지원서 보냈는데요, 이제 뭐하면되나요?
B: 기다리시면되요.
A: 연락주실껀가요?

B: 네, 이주안에 저희가 연락드릴꺼예요.