... at university, during his break (6)
I believe the answer is:
hiatus
'break' is the definition.
(hiatus is a kind of break)
'at university during his' is the wordplay.
'university' becomes 'u'.
'during' is an insertion indicator.
'at'+'u'='atu'
'atu' placed into 'his' is 'HIATUS'.
(Other definitions for hiatus that I've seen before include "Interval" , "Gap in continuity" , "A lacuna or interruption" , "Gap, interruption" , "A gap or lacuna" .)