from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The hue of that portion of the visible spectrum lying between green and indigo, evoked in the human observer by radiant energy with wavelengths of approximately 420 to 490 nanometers; any of a group of colors that may vary in lightness and saturation, whose hue is that of a clear daytime sky; one of the additive or light primaries; one of the psychological primary hues.
  • noun A pigment or dye imparting this hue.
  • noun Bluing.
  • noun An object having this hue.
  • noun Dress or clothing of this hue.
  • noun A person who wears a blue uniform.
  • noun A dress blue uniform, especially that of the US Army.
  • noun A member of the Union Army in the Civil War.
  • noun The Union Army.
  • noun A bluefish.
  • noun Any of various small blue butterflies of the family Lycaenidae.
  • noun The sky.
  • noun The sea.
  • adjective Of the color blue.
  • adjective Bluish or having parts that are blue or bluish, as the blue spruce and the blue whale.
  • adjective Having a gray or purplish color, as from cold or contusion.
  • adjective Wearing blue.
  • adjective Being a trail, as for skiing, marked with a sign having a blue square, indicating an intermediate level of difficulty.
  • adjective Relating to or being a blue state.
  • adjective Gloomy; depressed. synonym: depressed.
  • adjective Dismal; dreary.
  • adjective Puritanical; strict.
  • adjective Aristocratic; patrician.
  • adjective Indecent; risqué.
  • transitive & intransitive verb To make or become blue.
  • idiom (blue in the face) At the point of extreme exasperation.
  • idiom (into the blue) At a far distance; into the unknown.
  • idiom (out of the blue) From an unexpected or unforeseen source.
  • idiom (out of the blue) At a completely unexpected time.

from The Century Dictionary.

  • noun In archery: The third circle of the target, which is now usually colored blue. See target.
  • noun An arrow which hits this circle; a hit in the blue. By the present method of scoring, such a hit counts 5.
  • noun A name sometimes given to water-soluble induline.
  • noun Same as bleu-de-roi (which see).
  • noun A mixture of methylene-blue and methyl-violet.
  • To make blue; dye a blue color; color with bluing; make blue by heating, as metals, etc.
  • To blush.
  • Of the color of the clear sky; of the color of the spectrum between wave-lengths .505 and .415 micron, and more especially .487 to .460, or of such light mixed with white; azure; cerulean.
  • Livid; lead-colored: said of the skin or complexion as affected by cold, contusion, or fear (see blae): hence the phrase black and blue. See black.
  • Figuratively, afflicted with low spirits; despondent; depressed; hypochondriacal; having the blues.
  • Dismal; unpromising: applied to things: as, a blue lookout.
  • Inflexible; rigid; strict in morals or religion; puritanic: as, a blue Presbyterian: often in the form true blue (which see, below).
  • [With ref. to blue-stocking, q. v.] Learned; pedantic: applied to women.
  • Indecent; obscene: as, blue stories.
  • In Australia, the volcanic (basaltic) material in places overlying the Tertiary auriferous gravels.


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English blue, bleu, from Old French bleu, of Germanic origin; see bhel- in Indo-European roots.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Middle English blewe, partially from Old English *blǣw ("blue"; found in derivative blǣwen ("bluish")); and partially from Anglo-Norman blew, blef ("blue"), from Medieval Latin blāvus, blāvius ("blue"), from Old Frankish *blāw, *blāo (“blue”); both from Proto-Germanic *blēwaz (“blue, dark blue”), from Proto-Indo-European *bʰlēw- (“yellow, blond, grey”). Cognate with English dialectal blow ("blue"), Scots blue, blew ("blue"), North Frisian bla, blö ("blue"), Saterland Frisian blau ("blue"), Dutch blauw ("blue"), German blau ("blue"), Swedish blå ("blue"), Icelandic blár ("blue"), Latin flāvus ("yellow"), Middle Irish blá ("yellow"), Lithuanian blãvas ("blue"). Doublet of blae.


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  • Nick name for a person with red hair.

    February 17, 2007

  • "Blue color is everlastingly appointed by the Deity to be a source of delight." -John Ruskin

    April 8, 2009

  • TBT, I think Ruskin was talking about the Deity, not some weight-loss method.

    April 8, 2009

  • God of Sloughed Avoirdupois.

    April 8, 2009

  • Usage on barney.

    April 17, 2009

  • Name of a favorite song of ukulele players by Lou Handman, Grant Clarke & Edgar Leslie.

    September 22, 2009

  • Penny Arcade (09/04/09):

    "Blue is a flavor."

    "Yes. But only in the context of slush-based beverages."

    November 24, 2009

  • I'm blue (:

    June 23, 2010

  • what the hell you on about? brap! since when have you had the privelage to steel colours?

    January 18, 2011

  • "The pilot Juan Fernandez procured a deed of the isle named after him, and for some years resided there before Selkirk came. It is supposed, however, that he eventually contracted the blues upon his princely property, for after a time he returned to the main, and as report goes, became a very garrulous barber in the city of Lima."

    - Melville, The Encantadas, Sketch Seventh

    September 28, 2011

  • Australian slang: a fight

    June 17, 2017