Relax about start of Italian exam (5)
I believe the answer is:
resit
'exam' is the definition.
(as in resitting an exam)
'relax about start of italian' is the wordplay.
'relax' becomes 'rest' (I've seen this before).
'about' is an insertion indicator.
'start of' suggests taking the first letters.
The first letter of 'italian' is 'i'.
'rest' going around 'i' is 'RESIT'.
(Other definitions for resit that I've seen before include "Repeat (an exam)" , "take another exam" , "second exam" , "later exam" , "Take examination again" .)