Blue — Defs

01 a. 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 v…

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.
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.] Also: bluestocking
“The ladies were very blue and well informed.” — Thackeray.

“For his religion . . . 'T was Presbyterian, true blue.” — Hudibras.

02 n. 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, o…

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.poetically
2.
A pedantic woman; a bluestocking.[Colloq.]
3.
Low spirits; a fit of despondency; melancholy.[Colloq.]

Phrases & compounds

Berlin blue — Prussian blue.

Mineral blue — See under Mineral.

Prussian blue — See under Prussian.

03 v. t. To make blue; to dye of a blue color; to make blue by heating, as metals, etc.

imp. & p. p. Blued; p. pr. & vb. n. Bluing

1.
To make blue; to dye of a blue color; to make blue by heating, as metals, etc.