dark 最普通用词，指缺乏自然光线或人工照明，使某物漆黑无光或光线十分微弱。
dim 指光线不足或视力较差，不能清晰地看见物体。
black 侧重颜色是黑色的，有时也指无光的黑暗。
gloomy 指光线不足或部分光线受阻而出现的阴暗。
obscure 指因光线不充足而使物体灰暗不清，失去光泽或若隐若现。作借喻时指因复杂、深奥或含糊而难于理解。
vague 通常作借喻用，形容抽象事物。
grey 与dark意思相近，但侧重阴暗单调的意味。
参考例句
1. The item he intentionally obscured would make several interpretations possible. 他故意搞得含混不清的条款，可能会做出好几种解释。
2. On Time – Obscure term. Rarely used. 准时——晦涩的术语。很少使用。
3. How to solve obscure affection problem? 怎样解决模糊的情感问题？
英英解释
v.
1. make less visible or unclear
2. make unclear, indistinct, or blurred
3. make obscure or unclear
4. make undecipherable or imperceptible by obscuring or concealing
5. make difficult to perceive by sight adj.
1. not clearly understood or expressed
2. marked by difficulty of style or expression
3. difficult to find
4. not famous or acclaimed
5. not drawing attention
6. remote and separate physically or socially
