WordNet sense 1 (used to whiten laundry or hair or give it a bluish tinge):

bluing, blueing

WordNet sense 2 (the sky as viewed during daylight):

blue sky, blue air, wild blue yonder

WordNet sense 3 (blue color or pigment; resembling the color of the clear sky in the daytime):

blueness

WordNet sense 4 (the sodium salt of amobarbital that is used as a barbiturate; used as a sedative and a hypnotic):

Amytal, amobarbital sodium, blue angel, blue devil

WordNet sense 5 (suggestive of sexual impropriety):

gamey, gamy, juicy, naughty, racy, risque, spicy

WordNet sense 6 (in or characteristic of a region of the United States north of (approximately) the Mason-Dixon line):

northern

WordNet sense 7 (belonging to or characteristic of the nobility or aristocracy):

aristocratic, blue-blooded, gentle, patrician, aristocratical

WordNet sense 8 (of or belonging to or constituting the hereditary aristocracy especially as derived from feudal times):

noble

WordNet sense 9 (morally rigorous and strict):

puritan, puritanical, puritanic

WordNet sense 10 (characterized by strictness, severity, or restraint):

nonindulgent

WordNet sense 11 (low in spirits):

depressed, dispirited, down, downcast, downhearted, low, low-spirited, down in the mouth

WordNet sense 12 (affected or marked by low spirits):

dejected

WordNet sense 13 (characterized by profanity or cursing):

blasphemous, profane

WordNet sense 14 ((of behavior or especially language) characterized by obscenity or indecency):

dirty

WordNet sense 15 (of the color intermediate between green and violet; having a color similar to that of a clear unclouded sky):

bluish, blueish

WordNet sense 16 (being or having or characterized by hue):

chromatic

WordNet sense 17 (causing dejection):

dark, depressing, dingy, disconsolate, dismal, drab, drear, dreary, gloomy, grim, sorry, dispiriting, dingy

WordNet sense 18 (lacking cheer; depressing):

uncheerful