what does どことなくつかみどころがなくmean?


I came across this phrase in the sentence:

> 勘【かん】というものは、しょちゅう経験【けいけん】していながら、 **どことなくつかみどころがなく**
> 、いまの科学【かがく】ではまだその正体【しょうたい】が、明らか【あきらか】にされていない。(Soumatome N1 dokkai, p45)

My best effort to translate it naturally would be:

"Although we all often experience intuition, it is an intangible phenomenon
that modern science has yet to explain. "

But this is a guess with some added words. The expression can be googled as
'it is slippery in some way'.

Does anybody know this expression (or can suggest a good reference for such
expressions)?




The way I interpret it is that
[`つかみどころがない`](http://eow.alc.co.jp/search?q=%E3%81%A4%E3%81%8B%E3%81%BF%E3%81%A9%E3%81%93%E3%82%8D)
literally means something like "no places (you) can grab onto", and that it
can mean "eludes grasp", "elusive", "slippery", "vague", "unclear" and
similar, and that
[`どことなく`](http://eow.alc.co.jp/search?q=%E3%81%A9%E3%81%93%E3%81%A8%E3%81%AA%E3%81%8F)
means "somehow":

> 勘というものは、しょっちゅう経験していながら、どことなくつかみどころがなく、いまの科学ではまだその正体が、明らかにされていない。
>
> While being experienced quite often, the sixth sense somehow eludes our
> grasp. The way it physically manifests remains unclear to modern science.




The way I interpret it is that
[`つかみどころがない`](http://eow.alc.co.jp/search?q=%E3%81%A4%E3%81%8B%E3%81%BF%E3%81%A9%E3%81%93%E3%82%8D)
literally means something like "no places (you) can grab onto", and that it
can mean "eludes grasp", "elusive", "slippery", "vague", "unclear" and
similar, and that
[`どことなく`](http://eow.alc.co.jp/search?q=%E3%81%A9%E3%81%93%E3%81%A8%E3%81%AA%E3%81%8F)
means "somehow":

> 勘というものは、しょっちゅう経験していながら、どことなくつかみどころがなく、いまの科学ではまだその正体が、明らかにされていない。
>
> While being experienced quite often, the sixth sense somehow eludes our
> grasp. The way it physically manifests remains unclear to modern science.

