Waxy organic compound (6)
I believe the answer is:
sterol
'waxy organic compound' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sterol that I've seen before include "Chemical compound; ostler (anag.)" , "Ostler (anag) - natural alcohol" , "Waxy stuff" , "Solid form of alcohol" , "substance that doesn't dissolve" .)