of a colour intermediate between green and violet, as of the sky or sea on a sunny day

the clear blue sky

a blue silk shirt

deep blue eyes

(of a person or mood) melancholy, sad, or depressed

he's feeling blue

(of a film, joke, or story) having sexual or pornographic content

a blue movie

politically conservative

the successful blue candidate

blue colour or pigment

she was dressed in blue

the dark blue of his eyes

armchairs in pastel blues and greens

a small butterfly, the male of which is predominantly blue while the female is typically brown

a person who has represented Cambridge University (a Cambridge blue) or Oxford University (an Oxford blue) at a particular sport in a match between the two universities

a flyweight boxing blue

an argument or fight

did you have a blue or what?

a mistake

his tactical blue in saying the opposition wasn't ready to govern

a nickname for a red-headed person

only an Aussie could make a red-headed man ‘Blue.’

a supporter of the Conservative Party

make or become blue

the light dims, bluing the retina

blued paper

the day would haze, the air bluing with afternoon

wash (white clothes) with bluing

they blued the shirts and starched the uniforms

squander or recklessly spend (money)

they blued it all on sweets, toys, and cigarettes