HII region
noun
an area of interstellar space containing clouds of ionized hydrogen.
HII regions
-
pluralof HII region.plural
The grammatical form denoting more than one person, place, thing, or idea.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
These maps capture Galactic HII regions, planetary nebulae, and nearby galaxies at exceptional spatial scales.
From Science Daily ● Aug. 14, 2026
These sources include pulsars, planetary nebulae, compact HII regions -- which are dense, ionized gas clouds in space -- as well as distant galaxies that lie far beyond the Milky Way.
From Science Daily ● Jan. 24, 2026
