Free of duty (7)
'free of duty?' is the definition.
'at leisure' can be an answer for 'free' (I've seen this before). I'm not certain of the 'of duty?' bit.
'free of' is the wordplay.
I cannot really see how this works, but
'free' could be 'leisure' (I've seen this in another clue) and 'leisure' is located in the answer.
The remaining letters 'at' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for at leisure that I've seen before include "'Marry in haste, repent . . . . . . . . . '" , "resting" , "No hurry, having a rest" , "free" , "in an unhurried fashion" .)
'free of duty' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for relieve that I've seen before include "Take a job over from - bring aid" , "Break the sameness of" , "Free from obligation" , "cure" , "Take place of" .)