If you describe something as nebulous, you mean that it is vague and not clearly defined or not easy to describe.
例句
The notions we children were able to form of the great world beyond were exceedingly nebulous...我們這些孩子所能形成的對(duì)外部世界的認(rèn)識(shí)是非常模糊的。Music is such a nebulous thing.音樂是如此蒙之物。
英漢詞典釋義
adj.
朦朧的,模糊的
nebulous assurances of future cooperation對(duì)未來合作的含糊的保證
英英詞典釋義
Adjective
1. lacking definite form or limits;
"gropes among cloudy issues toward a feeble conclusion"- H.T.Moore"nebulous distinction between pride and conceit"
2. lacking definition or definite content;
"nebulous reasons""unfixed as were her general notions of what men ought to be"- Jane Austen