supergiant

American  

[soo-per-jahy-uhnt] / ˈsu pərˌdʒaɪ ənt /

noun

1. Astronomy. supergiant star.

2. an extremely large or powerful person, company, thing, etc.

---

adjective

1. extremely large; immense.

supergiant British  

/ ˈsuːpəˌdʒaɪənt /

noun

1. any of a class of extremely large and luminous stars, such as Betelgeuse, which have expanded to a large diameter and are eventually likely to explode as supernovae Compare giant star white dwarf

---

supergiant Scientific  

/ so̅o̅′pər-jī′ənt /

1. A star that is larger, brighter, and more massive than a giant star, being thousands of times brighter than the Sun and having a relatively short lifespan—only about 10 to 50 million years as opposed to around 5 billion years for the Sun. Supergiants, such as Betelgeuse and Rigel in Orion, are only found in young cosmic structures such as the arms of spiral galaxies. Red supergiants such as Betelgeuse are late-stage stars, having burned most of their hydrogen in an earlier stage as main-sequence stars, and now fuse helium into heavier elements through the triple alpha process. Blue supergiants such as Rigel are thought to have evolved from red giants, though some are considered main-sequence stars. Supergiants are thought to eventually undergo a supernova, ending up as neutron stars or black holes.

---

Etymology

Origin of supergiant

First recorded in 1925–30; super- + giant

Example Sentences

It is a red supergiant of extraordinary size, large enough to contain more than 400 million Suns.

From Science Daily • Jan. 10, 2026

"The infrared wavelengths of our observations overlap with an important silicate dust feature that's characteristic of some red supergiant spectra," Kilpatrick said.

From Science Daily • Oct. 9, 2025

"This tells us that the wind was very rich in carbon and less rich in oxygen, which also was somewhat surprising for a red supergiant of this mass."

From Science Daily • Oct. 9, 2025

That's the red supergiant Betelgeuse - one of the largest dying stars in the Milky Way!

From Space Scoop • Aug. 20, 2025

The X-rays are plausibly generated by friction in the disk of gas and dust accreted around Cyg X-l from its supergiant companion.

From "Cosmos" by Carl Sagan