nebulous
Pronunciation: /ˈnɛbjʊləs/
adjective
- 1in the form of a cloud or haze; hazy: a giant nebulous glow
- another term for nebular.

Origin:
late Middle English (in the sense 'cloudy'): from French nébuleux or Latin nebulosus, from nebula 'mist'. nebulous (sense 2) dates from the early 19th century