out of the blue
01
occurring without prior warning
예시들
The invitation to the party came out of the blue, and I could n't believe my luck.
He quit his job out of the blue, leaving everyone at the office stunned.
out of the blue
01
예상치 못하게, 갑자기
in a way that was not expected
02
갑자기, 예기치 않게
being quiet or still or inactive
