out of the blue
4 synonyms and 2 antonyms for out of the blue, grouped by meaning and by how common each one is.
Phrase — Without any warning or apparent cause; completely unexpectedly.
Synonyms
Everyday swaps
Common words most readers know — safe in any writing.
Less common
Still standard English, but they carry more weight.
Rare, literary or technical
Precise, but they will stand out — check the sense before using one.
without warning
out of nowhere
Antonyms
as expected
predictably
How to use out of the blue
The word patterns that sound natural to a native speaker.
came out of the blue
completely out of the blue
turned up out of the blue
Informal to neutral; fine in journalism and general writing.
Etymology
From the image of a bolt of lightning falling from a clear blue sky; the fuller form 'a bolt from the blue' is still used.
Full origin of out of the blue →Frequently asked questions
What is the difference between out of the blue and out of nowhere?
They are close in meaning and often interchangeable. Out of the blue emphasises that there was no warning after a period of nothing; out of nowhere emphasises the suddenness of the appearance itself, and is more often used of physical things, as in 'a cyclist came out of nowhere'.
Is it out of the blue or out the blue?
The standard form keeps 'of': out of the blue. 'Out the blue' is common in casual British and Caribbean speech but is best avoided in writing.
Why blue?
The blue is a clear sky. The phrase pictures lightning striking when there is not a cloud in sight, so nothing gave any warning.
