"滑溜溜" means "slippery" or "smooth". It's a word in the form of ABB. Specifically, this kind of adjective consists of a monosyllable "A" and then a postfix "BB" that strengthens the degree to enhance the expression of the whole word. For instance, 傻乎乎（silly）, 黑漆漆（black）, 軟綿綿 （soft）, 毛茸茸（fluffy) , 靜悄悄(quite) and so forth. This kind of words are generally used to describe the character of a thing (e.g. color, shape, property, texture, etc.) in a more vivid and expressive way.

It means what you touch or feel is very smooth.“溜溜”is used to stengthen its degree.But sometimes it can be used to describe a person which means the guy is very sly，he is not easily fooled.

这个词就是很滑的意思，“溜溜”两字一是用来加强表示很滑；二是为了音韵上的效果。

一般是说很光滑，也有说这个人滑溜溜的，就是说他不实在，很狡猾，tricky

就是很滑的意思 没别的 。