A time when flustered to get hold of Greek detective (7)
I believe the answer is:
maigret
'detective' is the definition.
(I've seen this before)
'a time when flustered to get hold of greek' is the wordplay.
'when flustered' indicates anagramming the letters.
'to get hold of' indicates putting letters inside.
'greek' becomes 'gr' (abbreviation for Greek).
'a'+'time'='atime'
'atime' with letters rearranged gives 'maiet'.
'maiet' going around 'gr' is 'MAIGRET'.
(Other definitions for maigret that I've seen before include "Simenon's Inspector" , "Policeman" , "Fictional detective" , "cracker?" , "Simenon''s detective-superintendent" .)