blue

Of the color intermediate between green and violet; having a color similar to that of a clear unclouded sky.

“October's bright blue weather”

“a blue flame”

Characterized by profanity or cursing.

“blue language”

Used to signify the Union forces in the American Civil War (who wore blue uniforms).

“a ragged blue line”

Morally rigorous and strict.

“blue laws”

Causing dejection.

“a blue day”

Belonging to or characteristic of the nobility or aristocracy.

“a blue family”

“blue blood”

Suggestive of sexual impropriety.

“a blue movie”

“blue jokes”

Filled with melancholy and despondency.

“lonely and blue in a strange city”

Used to whiten laundry or hair or give it a bluish tinge.

Any of numerous small butterflies of the family Lycaenidae.

Any organization or party whose uniforms or badges are blue.

“the Union army was a vast blue”

Blue clothing.

“she was wearing blue”

Blue color or pigment; resembling the color of the clear sky in the daytime.

“he had eyes of bright blue”

The sodium salt of amobarbital that is used as a barbiturate; used as a sedative and a hypnotic.

The sky as viewed during daylight.

“he shot an arrow into the blue”

Turn blue.