The colour of the clear sky or the deep sea, between green and violet in the visible spectrum, and one of the primary additive colours for transmitted light; the colour obtained by subtracting red and green from white light using magenta and cyan filters; or any colour resembling this
Of the higher-frequency region of the part of the electromagnetic spectrum which is relevant in the specific observation
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"
The colour of the sky In particular, a sky with no clouds, especially cumulus clouds This makes soaring trickier, as the glider pilot has less clues as to where to find the next reliable bit of lift Most pilots hate blue days Top
morally rigorous and strict; "blue laws"; "the puritan work ethic"; "puritanic distaste for alcohol"; "she was anything but puritanical in her behavior"
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"
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