blue-sky

American  

[bloo-skahy] / ˈbluˈskaɪ /

adjective

1. fanciful; impractical.

   blue-sky ideas.

2. (especially of securities) having dubious value; not financially sound.

   a blue-sky stock.

---

blue-sky British  

noun

1. (modifier) of or denoting theoretical research without regard to any future application of its result

   a blue-sky project

---

verb

1. to theorize (about something that may not lead to any practical application)

Etymology

Origin of blue-sky

First recorded in 1890–95

Example Sentences

For hours on a crisp, blue-sky day, kite flyers mingled with sign-wavers, sharing space on the National Mall as they pursued their dueling missions.

From Barron's • Mar. 28, 2026

Adding to the mistrust is that just over 60% of bucket one funding - for blue-sky research - goes directly to universities, who can then spend it how they like.

From BBC • Mar. 17, 2026

When an intern tells a patient that he believes kindness is the best medicine, J.D. tersely interrupts his blue-sky meliorism with a cold splash of reality.

From Salon • Feb. 26, 2026

“This should put a capper, in our opinion, on blue-sky hopes for substantial multiple expansion,” he wrote.

From MarketWatch • Feb. 5, 2026

And probably never even heard the blue-sky sound on their trumpets.

From "Maybe He Just Likes You" by Barbara Dee

Related Words

• absurd
• bizarre
• extravagant
• fantastic
• fantastical
• fictional
• imaginative
• offbeat
• preposterous
• unreal
• whimsical