nebula

noun

Etymology: Borrowed from Latin nebula (“little cloud, mist”). Akin to Ancient Greek νεφέλη (nephélē, “cloud”), German Nebel (“mist, nebula”), Old Norse nifl, Polish niebo (“sky, heaven”), Russian не́бо (nébo, “sky”).

1. A cloud in outer space consisting of gas or dust (e.g. a cloud formed after a star explodes).

   “Approximately 5 billion years ago, our solar nebula was formed as gravitational forces pulled interstellar gas and dust into a swirling mass around out newly formed sun.”

2. A white spot or slight opacity of the cornea.
3. A cloudy appearance in the urine.