Crossword Genius

Impermeable form of soil of some kind? (7)

Ross

I believe the answer is:

oilskin

I'm a little stuck... Click here to teach me more about this clue!

'impermeable form' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.

'soil of some kind?' is the wordplay.
I cannot quite see how this works, but
an anagram of 'soil' is 'oils' which is within the answer.
The remaining letters 'kin' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...

'of' is the link.

Can you help me to learn more?

(Other definitions for oilskin that I've seen before include "material" , "Waterproof garment" , "Raincoat" , "Heavy waterproofed cloth" , "Waterproof cloth as for sailors" .)

I've seen this clue in the Evening Standard.
Want a hint initially instead of a full solution? Install my app