What does "h ii region" mean?

A large nebula of gas and plasma of glowing low density in which star formation has recently taken place.

What is a synonym for "h ii region"?

Common synonyms include: nebulae.

noun

noun ·Rare ·Advanced level

Noun

1
A large nebula of gas and plasma of glowing low density in which star formation has recently taken place.

From a being region of space having H_(II) emission lines in its spectrum.