Counsel possibly slick, getting Charlie off (4)
I believe the answer is:
silk
'counsel' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for silk that I've seen before include "Smooth material" , "Superior barrister" , "Fabric made from fine threads of certain worm" , "Fabric obtained from the cocoon of a worm" , "brief" .)