Definitions of blue:

• noun:   any of numerous small chiefly blue butterflies of the family Lycaenidae
• noun:   blue clothing

  Example: "She was wearing blue"

• noun:   the color of the clear sky in the daytime

  Example: "He had eyes of bright blue"

• noun:   any organization or party whose uniforms or badges are blue

  Example: "The Union army was a vast blue"

• noun:   the sodium salt of amobarbital that is used as a barbiturate; used as a sedative and a hypnotic
• noun:   the sky as viewed during daylight

  Example: "He shot an arrow into the blue"

• noun:   used to whiten laundry or hair or give it a bluish tinge
• verb:   turn blue
• adjective:   used to signify the Union forces in the Civil War (who wore blue uniforms)

  Example: "A ragged blue line"

• adjective:   suggestive of sexual impropriety

  Example: "A blue movie"

• adjective:   causing dejection

  Example: "A blue day"

• adjective:   having a color similar to that of a clear unclouded sky

  Example: "October's bright blue weather- Helen Hunt Jackson"

• adjective:   low in spirits

  Example: "Lonely and blue in a strange city"

• adjective:   characterized by profanity or cursing

  Example: "Blue language"

• adjective:   belonging to or characteristic of the nobility or aristocracy

  Example: "A blue family"

• name:  A surname (common: 1 in 9090 families; popularity rank in the U.S.: #1162)