adjective

1. having the color of the clear sky or the deep sea
2. having a bluish cast or tinge

3. Etymology: infl. by ME blo < ON blā, livid

   livid: said of the skin
4. sad and gloomy; depressed or depressing
5. balefully murky the air was blue with oaths
6. puritanical; rigorous
7. wearing blue garments Blue Nuns
8. Informal indecent; risqué; suggestive

Etymology: ME & OFr bleu < Frank *blao < IE base *bhlē-wos, light-colored, blue, blond, yellow > L flavus, yellow, Brythonic blawr, gray, OE blæwen, blue, Ger blau

noun

1. the color of the clear sky or the deep sea; any color between green and violet in the spectrum
2. any blue pigment or dye
3. bluing
4. anything colored blue, as the third circle of an archer's target
5. 1. blue clothing
   2. a person or group wearing a blue uniform
   3. ☆ a Union soldier
   4. a sailor's blue uniform
6. bluestocking
7. ☆ bluefish
8. blueline: usually used in pl.

transitive verb, intransitive verb blued, bluing blu′·ing or blueing blue′·ing