Definition of "quasar" []

• An extremely distant, and thus old, celestial object whose power output is several thousand times that of our entire galaxy. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "A quasar is a bright object full of energy powered by a black hole."
• "A quasar is a compact region in the center of a massive galaxy surrounding the central supermassive black hole."
• "Astronomers have discovered the largest and oldest mass of water ever detected in the universe - a gigantic, 12-billion-year-old cloud harboring 140 trillion times more water than all of Earth's oceans combined. supermassive black hole called a quasar located 12 billion light-years from Earth."