Astronomy. Also called diffuse nebula. a cloud of interstellar gas and dust. Compare dark nebula, emission nebula, reflection nebula. (formerly) any celestial object that appears nebulous, hazy, or fuzzy, and extended in a telescope view.
Pathology. a faint opacity in the cornea. cloudiness in the urine.
any liquid medication prepared for use as a spray.
(astronomy) a diffuse cloud of particles and gases (mainly hydrogen) that is visible either as a hazy patch of light (either an emission or a reflection nebula) or an irregular dark region against a brighter background (dark nebula) Compare planetary nebula
(pathol) opacity of the cornea cloudiness of the urine