Milky Way

American  

[mil-kee wey] / ˈmɪl ki ˈweɪ /

noun

Astronomy.

1. the spiral galaxy containing our solar system: with the naked eye it appears as a faint luminous band stretching across the heavens, composed of approximately a trillion stars, most of which are too distant to be seen individually.

---

Milky Way British  

noun

1. the diffuse band of light stretching across the night sky that consists of millions of faint stars, nebulae, etc, within our Galaxy

2. another name for the Galaxy

---

Milky Way Scientific  

/ mĭl′kē /

1. The spiral galaxy that contains our solar system. Made up of an estimated two hundred billion stars or more, it is seen from Earth as an irregular band of hazy light across the night sky. The solar system is located in one of the revolving spiral arms, about 50 light-years north of the galactic plane and some 27,700 light-years from the galaxy's center, which lies in the direction of the constellation Sagittarius. It takes approximately 250 million years for the solar system to orbit the galactic center, which is believed to contain a massive black hole. The Milky Way measures about 100,000 light-years in diameter and is the second largest galaxy, after the Andromeda Galaxy, in the cluster known as the Local Group.

2. See also spiral galaxy

---

Milky Way Cultural  

1. The galaxy to which our sun belongs.

---

Discover More

The Milky Way is also the swath of light in the night sky produced by the other stars in the galaxy.

Etymology

Origin of Milky Way

First recorded in 1350–1400; Middle English, translation of Latin via lactea; galaxy

Example Sentences

Astronomers have detected an excess of gamma radiation at the center of the Milky Way, which could be produced when dark matter particles collide and annihilate.

From Science Daily • Apr. 10, 2026

A special category known as supermassive black holes, including the one at the center of the Milky Way, can contain millions or even billions of times the mass of the sun.

From Science Daily • Mar. 30, 2026

The Milky Way itself may have once gone through a quasar phase, although it is not active today.

From Science Daily • Mar. 30, 2026

"Are there differences between their formation? Where is their oxygen distributed now? Is our Milky Way different or unique in any way? Those are the questions we want to answer."

From Science Daily • Mar. 23, 2026

We know N., the number of stars in the Milky Way Galaxy, fairly well, by careful counts of stars in small but representative regions of the sky.

From "Cosmos" by Carl Sagan