a nebula is a form of:

Nebula



noun — Plural: Nebulae, nebulas
1.
(cluster of stars, vague) ពពក, ផ្សែងភ្លើង
ENGLISH MEANING
noun — Plural: Nebulae, nebulas
1.
A faint, cloudlike, self-luminous mass of matter situated beyond the solar system among the stars. True nebulae are gaseous; but very distant star clusters often appear like them in the telescope.
2.
A white spot or a slight opacity of the cornea.
3.
A cloudy appearance in the urine.