# out of the blue

Pronunciation: US say "owt uv thuh BLOO" /ˌaʊt əv ðə ˈblu/; UK say "owt ov thuh BLOO" /aʊt ɒv ðə bluː/; AUS say "owt-uhv-thuh-BLOO" /aʊt ɒv ðə bluː/

## Idiom

1. Suddenly and without any warning or preparation; happening when no one expects it.
   - Simple: Suddenly, when no one expected it at all.
   - _His resignation came out of the blue, stunning the entire department._
   - _Out of the blue, an old college friend showed up at my front door._

## Origin

This is a shortened form of "out of the blue sky," likening an unexpected event to lightning or rain that arrives suddenly from a cloudless sky.

Source: DictionaryAI, https://dictionaryai.com/define/out-of-the-blue (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).