Handy man in challenging (7)
I believe the answer is:
defiant
'challenging' is the definition.
(similar in meaning)
'handy man in' is the wordplay.
'handy' becomes 'deft' (I've seen this before).
'man' becomes 'Ian' (man's name).
'in' means one lot of letters goes inside another.
'deft' going around 'ian' is 'DEFIANT'.
(Other definitions for defiant that I've seen before include "showing teeth!" , "Openly resisting" , "Mutinous" , "Unyielding" , "Fainted, being rebellious" .)