What does blue mean?
Blue is one of the most familiar words in English, denoting the colour of the clear sky and the deep sea — a hue lying between green and violet on the spectrum. It appears constantly in everyday description of nature, art, clothing, and design, and its figurative uses are equally rich: to feel 'blue' is to be sad, a 'blue' joke is indecent, and something happening 'out of the blue' arrives unexpectedly. In politics, blue often represents conservative parties in Britain and America, though the association reverses across parts of Europe. The word entered Middle English from Old French, ultimately tracing back through Germanic roots shared with other European languages. Remarkably, many ancient languages had no distinct word for blue at all, treating it as a shade of green or black — making 'blue' not just a colour term but a small window into how human perception and language evolved together.
The colour between green and violet in the spectrum, like that of a cloudless sky.
"Her favourite colour has always been blue."
Uncountable when referring to the colour generally.
Having the colour of a clear sky or deep sea.
"A blue ribbon was tied around the parcel."
(Informal, chiefly British) To spend money extravagantly or wastefully.
"He blued his entire bonus on a weekend in Las Vegas."
Colloquial and dated; rare outside British usage.
The plural 'blues' commonly refers to shades or varieties of the colour, or to feelings of sadness (as in 'the blues').
"The room was decorated in cool blues and greens."
For most of history, ancient languages didn't have a word for blue at all — Homer described the sea as 'wine-dark', and it was one of the last colours humans bothered naming.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of blue
The word 'blue' came into Middle English from Old French 'bleu', which itself derives from a Germanic root (Frankish *blāo), related to Old High German 'blāo' meaning shining or blue. This makes it one of the relatively few English colour terms borrowed via Romance from Germanic origins. Cognates appear across Germanic languages, including Dutch 'blauw' and German 'blau'.
Word family
Usage notes
As an adjective, 'blue' is fully standard in all registers. The informal senses — feeling sad, indecent content, and wasting money (chiefly British) — are colloquial and should be used carefully in formal writing. In politics, 'blue' signifies conservative parties in the UK and US but left-leaning parties in much of continental Europe.
Don't confuse with
'Blew' is the past tense of the verb 'blow', while 'blue' is a colour; they are homophones with entirely unrelated meanings.