Meaning & Origin

The idiom blends the image of a sudden “bolt from the blue”, a lightning strike from a clear sky, with surprise. It describes events that arrive with no advance sign.

Pronunciation Guide

Say it as OUT of the BLUE: /aʊt əv ðə bluː/.

Usage & Sentence Examples

• The offer came out of the blue.
   
• She showed up out of the blue at my door.
   
• Out of the blue, the app went viral.

Synonyms

• unexpectedly
• all of a sudden
• without warning
• from nowhere
• unannounced