Bureaucrat leaving institute spies opening for lover (8)
I believe the answer is:
official
'bureaucrat' is the definition.
(I've seen this before)
'leaving institute spies opening for lover' is the wordplay.
'leaving' becomes 'off' (as in 'I'm off').
'institute' becomes 'i' (common abbreviation as in MIT).
'spies' becomes 'CIA' (Central Intelligence Agency).
'opening for' suggests taking the first letters.
The initial letter of 'lover' is 'l'.
'off'+'i'+'cia'+'l'='OFFICIAL'
(Other definitions for official that I've seen before include "Authentic - officer" , "Person appointed by authority" , "Authorised - formal" , "Formally approved" , "Legitimate" .)