IPA: /ˈnɛb.jə.ləs.nəs/
KK: /ˈnɛb.jə.ləs.nəs/
The quality of being unclear, vague, or not well-defined.
The nebulousness of his explanation left everyone confused.
Nebulousness → It is formed from "nebulous" (from Latin "nebulosus", meaning full of mist or cloud) and the suffix "-ness" (meaning the state or quality of). The word "nebulousness" refers to the quality of being vague or unclear, much like a cloud or mist.
Think of something that is 'full of mist' ('nebulous') and how that creates a sense of vagueness or lack of clarity, which is what 'nebulousness' means.