Guy, having consumed drug without limits in retreat, is receptive to treatment (7)
I believe the answer is:
curable
'receptive to treatment' is the definition.
I can't judge whether this definition defines the answer.
'guy having consumed drug without limits in retreat' is the wordplay.
'guy' becomes 'cable' (I've seen this in other clues).
'having consumed' means one lot of letters goes inside another.
'without limits' indicates the central letters (letters at the edges or 'limits' are removed).
'in retreat' shows that the letters should be reversed in order.
The central letters of 'drug' are 'ru'.
'ru' reversed gives 'ur'.
'cable' placed around 'ur' is 'CURABLE'.
'is' acts as a link.
Can you help me to learn more?
(Other definitions for curable that I've seen before include "suitable for smoking?" , "Responsive to treatment" , "Able to be made healthy" .)