(1) (pathology) a faint cloudy spot on the cornea
(2) An immense cloud of gas (mainly hydrogen) and dust in interstellar space
(3) Cloudiness of the urine
(4) A medicinal liquid preparation intended for use in an atomizer
From . Akin to Greek νεφέλη, "cloud", German Nebel, "mist", "nebula", Old Norse nifl.