Definition

1. Noun:

   • A color: The color of the clear sky on a sunny day; the color between green and violet in the visible spectrum.
   • The sky or the sea: Used poetically or descriptively to refer to the sky or a large body of water.
   • A feeling of sadness: A state of melancholy or depression (often used with 'the').
   • A person or team: A sports player or team representing a university (especially Oxford or Cambridge) or wearing blue uniforms.
   • A type of butterfly: Any of numerous small butterflies of the family Lycaenidae, often with blue coloring on their wings.
   • A chemical substance: A blue dye, pigment, or a specific chemical compound like a barbiturate sedative.

2. Adjective:

   • Of the color blue: Having the hue of a clear sky.
   • Sad, melancholy: Feeling or showing unhappiness or depression.
   • Risqué, indecent: Referring to jokes, language, or material that is sexually suggestive or profane.
   • Aristocratic, noble: Belonging to or characteristic of high social rank (from the term 'blue blood').
   • Rigidly moral, puritanical: Characterized by strict moral codes, especially regarding pleasure.
   • Relating to a political faction: Pertaining to a group whose identifying color is blue, such as the Union (Northern) forces in the American Civil War.

3. Verb:

   • To make or become blue: To give a blue color to something, or to turn the color blue.

Usage Examples

• Noun (Color):
  • She painted her room a bright blue.
  • He had eyes of a deep, vivid blue.
• Noun (Sky/Sea):
  • The balloon disappeared into the blue.
  • He loves sailing on the blue.
• Noun (Sadness):
  • She's been suffering from the blues lately.
  • Listening to that music gives me the blues.
• Adjective (Color):
  • They live in a blue house with a white door.
  • The blue flame indicates complete combustion.
• Adjective (Sad):
  • He felt blue after his friend moved away.
  • It was a blue, rainy Monday morning.
• Adjective (Indecent):
  • He told a rather blue joke at the party.
  • The comedian's act was full of blue language.
• Verb:
  • The cold weather caused his lips to blue.
  • She blued the fabric with indigo dye.

Advanced Usage

• "Out of the blue": Suddenly and unexpectedly.
  • His resignation came completely out of the blue.
• "Once in a blue moon": Very rarely.
  • We only see them once in a blue moon.
• "Blue blood": Noble or aristocratic lineage.
  • The family prided themselves on their blue blood.
• "Blue-collar": Relating to manual work or workers (Note: This is a compound word listed as a variant).
• "True blue": Extremely loyal and faithful.
  • He's a true blue supporter of the team.

Variants and Related Words

• Bluish/Blueish (adj): Somewhat blue.
• Blueness (n): The quality or state of being blue.
• Blueberry (n): A small blue fruit.
• Blueprint (n): A detailed plan or technical drawing.
• Blues (n, plural): A genre of music characterized by a melancholic mood; also, feelings of depression.
• Blue-collar (adj): Pertaining to manual labor jobs.
• Blue-chip (adj): Denoting companies or stocks considered reliable and profitable.

Synonyms

• Azure, Cobalt, Sapphire (for the color).
• Melancholy, Gloomy, Downcast (for sadness).
• Risqué, Ribald, Bawdy (for indecent content).
• Aristocratic, Patrician, Noble (for high social rank).

Related Phrasal Verbs/Phrases

• Blue out: (Rare) To become blue or to make something blue.
• Blue up: (Informal, rare) To become sad or depressed.

Related Idioms

• Scream/shout blue murder: To protest or complain very loudly and angrily.
  • He started shouting blue murder when he saw the parking ticket.
• Between the devil and the deep blue sea: In a difficult situation where both choices are bad.
  • I'm between the devil and the deep blue sea; I can either take a pay cut or lose my job.
• Talk a blue streak: To talk very quickly and at great length.
  • Once she gets started, she can talk a blue streak for hours.

Noun

1. any of numerous small butterflies of the family Lycaenidae
2. the sodium salt of amobarbital that is used as a barbiturate; used as a sedative and a hypnotic
3. used to whiten laundry or hair or give it a bluish tinge
4. the sky as viewed during daylight
   • he shot an arrow into the blue
5. any organization or party whose uniforms or badges are blue
   • the Union army was a vast blue
6. blue clothing
   • she was wearing blue
7. blue color or pigment; resembling the color of the clear sky in the daytime
   • he had eyes of bright blue

Adjective

1. 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
2. morally rigorous and strict
   • the puritan work ethic
   • puritanic distaste for alcohol
   • she was anything but puritanical in her behavior
3. 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
4. suggestive of sexual impropriety
   • a blue movie
   • blue jokes
   • he skips asterisks and gives you the gamy details
   • a juicy scandal
   • a naughty wink
   • naughty words
   • racy anecdotes
   • a risque story
   • spicy gossip
5. characterized by profanity or cursing
   • foul-mouthed and blasphemous
   • blue language
   • profane words
6. filled with melancholy and despondency
   • gloomy at the thought of what he had to face
   • gloomy predictions
   • a gloomy silence
   • took a grim view of the economy
   • the darkening mood
   • lonely and blue in a strange city
   • depressed by the loss of his job
   • a dispirited and resigned expression on her face
   • downcast after his defeat
   • feeling discouraged and downhearted
7. used to signify the Union forces in the American Civil War (who wore blue uniforms)
   • a ragged blue line
8. of the color intermediate between green and violet; having a color similar to that of a clear unclouded sky
   • October's bright blue weather- Helen Hunt Jackson
   • a blue flame
   • blue haze of tobacco smoke

Verb

1. turn blue