IPA: /nɛˈbjuːləsli/
KK: /ˈnɛb.jə.ləs.li/
In a way that is unclear or vague, as if seen through a mist or haze.
The plan was nebulously defined, leaving everyone confused about their roles.
Nebulously → It is formed from "nebula" (from Latin, meaning mist or cloud) and the suffix "-ously" (meaning in a manner of). The word "nebulously" means in a manner that is vague or unclear, like a mist or cloud.
Think of something that is like a 'cloud' or 'mist' ('nebula') — that's why nebulously means something unclear or vague.