Waxed middle of torso to wear frock (5)
I believe the answer is:
grown
'waxed' is the definition.
Both the answer and definition are adjectives. Maybe you can see an association between them that I can't see?
'middle of torso to wear frock' is the wordplay.
'middle of' indicates the central letters.
'to wear' indicates putting letters inside (to wear something is to be covered up by it).
'frock' becomes 'gown' (gown is a kind of frock).
The middle letter of 'torso' is 'r'.
'r' put inside 'gown' is 'GROWN'.
Can you help me to learn more?
(Other definitions for grown that I've seen before include "Wrong (anag)" , "Increased; developed" , "Matured" , "Mature; raised" , "increased in stature?" .)