out of the blue

Definition

Unexpectedly; without warning or preparation.

Etymology

Short for out of the blue sky, likening an unexpected event to lightning or rain coming suddenly from a cloudless sky.

Example Sentences

• "After I hadn’t heard from her in six months, she called me out of the blue to meet for lunch."
• "I really can't understand how something like this could simply pop up out of the blue."
• "I deckhanded on a fish boat for four years and knew no fisherman likes to be called out of the blue and have his numbers demanded!"