1. 无名的；鲜为人知的；默默无闻的
    If something or someone is obscure, they are unknown, or are known by only a few people.

    e.g. The origin of the custom is obscure...
           这一习俗的起源鲜为人知。
    e.g. The hymn was written by an obscure Greek composer for the 1896 Athens Olympics.
           这首赞歌是希腊一位名不见经传的作曲家为1896年的雅典奥运会创作的。

2. （通常指因内容繁琐）晦涩的，费解的，难懂的
    Something that is obscure is difficult to understand or deal with, usually because it involves so many parts or details.

    e.g. The contracts are written in obscure language...
           这些合同的语言晦涩难懂。
    e.g. Richard's statement was disgracefully obscure.
           理查德的声明隐晦费解，真是丢人。

3. 遮掩；遮蔽；使模糊不清
    If one thing obscures another, it prevents it from being seen or heard properly.

obscure

    e.g. Trees obscured his vision; he couldn't see much of the Square's southern half...
           树木遮挡了他的视线，南半广场的一大部分他都无法看清。
    e.g. One wall of the parliament building is now almost completely obscured by a huge banner.
           议会大楼的一面墙现在几乎被一条巨型横幅完全盖住了。

4. 使晦涩；使费解；使难懂
    To obscure something means to make it difficult to understand.

    e.g. ...the jargon that frequently obscures educational writing...
           经常让普教著作变得艰深晦涩的术语
    e.g. This issue has been obscured by recent events.
           最近发生的一些事件使这一问题变得混淆不清。