1. [n]  any of numerous small chiefly blue butterflies of the family Lycaenidae
2. [n]  the sodium salt of amobarbital that is used as a barbiturate; used as a sedative and a hypnotic
3. [n]  blue clothing; "she was wearing blue"
4. [n]  the color of the clear sky in the daytime; "he had eyes of bright blue"
5. [n]  any organization or party whose uniforms or badges are blue; "the Union army was a vast blue"
6. [n]  the sky as viewed during daylight; "he shot an arrow into the blue"
7. [n]  used to whiten laundry or hair or give it a bluish tinge
8. [adj]  causing dejection; "a blue day"; "the dark days of the war"; "a week of rainy depressing weather"; "a disconsolate winter landscape"; "the first dismal dispiriting days of November"; "a dark gloomy day"; "grim rainy weather"
9. [adj]  having a color similar to that of a clear unclouded sky; "October's bright blue weather"- Helen Hunt Jackson; "a blue flame"; "blue haze of tobacco smoke"
10. [adj]  characterized by or marked with a bluish color; "a blue fox"; "the great blue whale"; "a blue spruce"
11. [adj]  tinged with blue or purple from cold or contusion; "the children's lips are blue from cold"; "a blue bruise"
12. [adj]  characterized by profanity or cursing; "foul-mouthed and blasphemous"; "blue language"; "profane words"
13. [adj]  low in spirits; "lonely and blue in a strange city"; "depressed by the loss of his job"; "a dispirited and resigned expression on her face"; "downcast after his defeat"; "feeling discouraged and downhearted"
14. [adj]  belonging to or characteristic of the nobility or aristocracy; "an aristocratic family"; "aristocratic Bostonians"; "aristocratic government"; "a blue family"; "blue blood"; "the blue-blooded aristocracy"; "of gentle blood"; "patrician landholders of the American South"; "aristocratic bearing"; "aristocratic features"; "patrician tastes"
15. [adj]  used to signify the Union forces in the Civil War (who wore blue uniforms); "a ragged blue line"
16. [adj]  suggestive of sexual impropriety; "a blue movie"; "blue jokes"; "he skips asterisks and gives you the gamy details"; "a juicy scandal"; "a naughty wink"; "naughty words"; "racy anecdotes"; "a risque story"; "spicy gossip"
17. [adj]  wearing blue; "the painting is called `the blue boy'"; "the blue team"
18. [v]  turn blue

1. \Blue\, a. [Compar. {Bluer}; superl. {Bluest}.] [OE. bla,
   blo, blew, blue, Sw. bl?, D. blauw, OHG. bl?o, G. blau; but
   influenced in form by F. bleu, from OHG. bl[=a]o.]
   1. Having the color of the clear sky, or a hue resembling it,
      whether lighter or darker; as, the deep, blue sea; as blue
      as a sapphire; blue violets. ``The blue firmament.''
      --Milton.
   2. Pale, without redness or glare, -- said of a flame; hence,
      of the color of burning brimstone, betokening the presence
      of ghosts or devils; as, the candle burns blue; the air
      was blue with oaths.
   3. Low in spirits; melancholy; as, to feel blue.
   4. Suited to produce low spirits; gloomy in prospect; as,
      thongs looked blue. [Colloq.]
   5. Severe or over strict in morals; gloom; as, blue and sour
      religionists; suiting one who is over strict in morals;
      inculcating an impracticable, severe, or gloomy mortality;
      as, blue laws.
   6. Literary; -- applied to women; -- an abbreviation of
      bluestocking. [Colloq.]
            The ladies were very blue and well informed.
                                                  --Thackeray.
   {Blue asbestus}. See {Crocidolite}.
   {Blue black}, of, or having, a very dark blue color, almost
      black.
   {Blue blood}. See under {Blood}.
   {Blue buck} (Zo["o]l.), a small South African antelope
      ({Cephalophus pygm[ae]us}); also applied to a larger
      species ({[AE]goceras leucoph[ae]u}s); the blaubok.
   {Blue cod} (Zo["o]l.), the buffalo cod.
   {Blue crab} (Zo["o]l.), the common edible crab of the
      Atlantic coast of the United States ({Callinectes
      hastatus}).
   {Blue curls} (Bot.), a common plant ({Trichostema
      dichotomum}), resembling pennyroyal, and hence called also
      {bastard pennyroyal}.
   {Blue devils}, apparitions supposed to be seen by persons
      suffering with {delirium tremens}; hence, very low
      spirits. ``Can Gumbo shut the hall door upon blue devils,
      or lay them all in a red sea of claret?'' --Thackeray.
   {Blue gage}. See under {Gage}, a plum.
   {Blue gum}, an Australian myrtaceous tree ({Eucalyptus
      globulus}), of the loftiest proportions, now cultivated in
      tropical and warm temperate regions for its timber, and as
      a protection against malaria. The essential oil is
      beginning to be used in medicine. The timber is very
      useful. See {Eucalyptus}.
   {Blue jack}, {Blue stone}, blue vitriol; sulphate of copper.
   {Blue jacket}, a man-of war's man; a sailor wearing a naval
      uniform.
   {Blue jaundice}. See under {Jaundice}.
   {Blue laws}, a name first used in the eighteenth century to
      describe certain supposititious laws of extreme rigor
      reported to have been enacted in New Haven; hence, any
      puritanical laws. [U. S.]
   {Blue light}, a composition which burns with a brilliant blue
      flame; -- used in pyrotechnics and as a night signal at
      sea, and in military operations.
   {Blue mantle} (Her.), one of the four pursuivants of the
      English college of arms; -- so called from the color of
      his official robes.
   {Blue mass}, a preparation of mercury from which is formed
      the blue pill. --McElrath.
   {Blue mold}, or mould, the blue fungus ({Aspergillus
      glaucus}) which grows on cheese. --Brande & C.
   {Blue Monday}, a Monday following a Sunday of dissipation, or
      itself given to dissipation (as the Monday before Lent).
   {Blue ointment} (Med.), mercurial ointment.
   {Blue Peter} (British Marine), a blue flag with a white
      square in the center, used as a signal for sailing, to
      recall boats, etc. It is a corruption of blue repeater,
      one of the British signal flags.
   {Blue pill}. (Med.)
      (a) A pill of prepared mercury, used as an aperient, etc.
      (b) Blue mass.
   {Blue ribbon}.
      (a) The ribbon worn by members of the order of the Garter;
          -- hence, a member of that order.
      (b) Anything the attainment of which is an object of great
          ambition; a distinction; a prize. ``These
          [scholarships] were the --blue ribbon of the
          college.'' --Farrar.
      (c) The distinctive badge of certain temperance or total
          abstinence organizations, as of the --Blue ribbon
          Army.
   {Blue ruin}, utter ruin; also, gin. [Eng. Slang] --Carlyle.
   {Blue spar} (Min.), azure spar; lazulite. See {Lazulite}.
   {Blue thrush} (Zo["o]l.), a European and Asiatic thrush
      ({Petrocossyphus cyaneas}).
   {Blue verditer}. See {Verditer}.
   {Blue vitriol} (Chem.), sulphate of copper, a violet blue
      crystallized salt, used in electric batteries, calico
      printing, etc.
   {Blue water}, the open ocean.
   {To look blue}, to look disheartened or dejected.
   {True blue}, genuine and thorough; not modified, nor mixed;
      not spurious; specifically, of uncompromising
      Presbyterianism, blue being the color adopted by the
      Covenanters.
      For his religion . . . 'T was Presbyterian, true blue.
                                                  --Hudibras.
   

2. \Blue\ (bl[=u]), n.
   1. One of the seven colors into which the rays of light
      divide themselves, when refracted through a glass prism;
      the color of the clear sky, or a color resembling that,
      whether lighter or darker; a pigment having such color.
      Sometimes, poetically, the sky.
   2. A pedantic woman; a bluestocking. [Colloq.]
   3. pl. [Short for blue devils.] Low spirits; a fit of
      despondency; melancholy. [Colloq.]
   {Berlin blue}, Prussian blue.
   {Mineral blue}. See under {Mineral}.
   {Prussian blue}. See under {Prussian}.
   

3. \Blue\, v. t. [imp. & p. p. {Blued}; p. pr. & vb. n.
   {Bluing}.]
   To make blue; to dye of a blue color; to make blue by
   heating, as metals, etc.
   

A language proposed by Softech to meet the DoD Ironman requirements which led to Ada. ["On the BLUE Language Submitted to the DoD", E.W. Dijkstra, SIGPLAN Notices 13(10):10-15 (Oct 1978)].

generally associated with purple (Ex. 25:4; 26:1, 31, 36, etc.). It is supposed to have been obtained from a shellfish of the Mediterranean, the Helix ianthina of Linnaeus. The robe of the high priest's ephod was to be all of this colour (Ex. 28:31), also the loops of the curtains (26:4) and the ribbon of the breastplate (28:28). Blue cloths were also made for various sacred purposes (Num. 4:6, 7, 9, 11, 12). (See COLOUR.)