(bl) adjective blu·er, blu·est
1. Having the color of the clear sky.
2. Dismal; dreary; melancholy; despondent; also, depressing; discouraging: Things look blue.
3. Severe or Puritanic; strict: blue laws.
4. Faithful; genuine; sterling: He is true blue.
5. Livid, as from contusion, cold, or fear.
6. Devoted to literature; pedantic: said of women.
7. Denoting venous blood that shows through the skin.
8. Designating a flame, as of a candle, where the red glare is absent: said to be an omen of the presence of evil spirits.
—noun
1. One of the chief colors of the spectrum, between green and violet; the color of the clear sky; azure.
2. The coloring matter or pigment used for imparting a blue color.
3. A blue print.
4. One who wears blue clothing or insignia.
5. plural See BLUES.
6. The bluish-gray winter coat of a deer.
7. A small butterfly of the family Lycaenidae.
8. A bluestocking.
—out of the blue At an unexpected time and from an unsuspected source; completely unforeseen.
—v.t. blued, blu·ing
1. To make blue.
2. To treat with bluing. [<OF bleu, ult. <Gmc.]
—blue′ly adverb
—blue′ness noun

(bl) noun
1. A soldier of the Federal Army in the American Civil War. Compare GRAY.
2. Brit. An athlete wearing the colors of his university in contests between Oxford (dark blue) and Cambridge (light blue).
3. Brit. A member of the Royal Horse Guard.