1. 滑溜溜的;滑的
    Something that is slippery is smooth, wet, or oily and is therefore difficult to walk on or to hold.

    e.g. The tiled floor was wet and slippery...
           瓷砖地面又湿又滑。
    e.g. Motorists were warned to beware of slippery conditions.
           提醒驾车人要当心路滑。

2. 滑头的;靠不住的;狡猾的
    You can describe someone as slippery if you think that they are dishonest in a clever way and cannot be trusted.

    e.g. He is a slippery customer, and should be carefully watched.
           他是一个狡猾的顾客，要小心提防。

3. 滑向深渊的道路
    If someone is on a slippery slope, they are involved in a course of action that is difficult to stop and that will eventually lead to failure or trouble.

slippery的翻译

    e.g. The company started down the slippery slope of believing that they knew better than the customer.
           该公司认为他们比顾客更了解情况，而有这种想法注定是要失败的。