Arrest happened originally outside front of restaurant (9)
I believe the answer is:
apprehend
'arrest' is the definition.
('apprehend' can be a synonym of 'arrest')
'happened originally outside front of restaurant' is the wordplay.
'originally' indicates anagramming the letters.
'outside' indicates putting letters inside.
'front of' suggests taking the first letters.
The initial letter of 'restaurant' is 'r'.
'happened' is an anagram of 'appehend'.
'appehend' placed around 'r' is 'APPREHEND'.
(Other definitions for apprehend that I've seen before include "Arrest (someone)" , "Arrest - grasp" , "Be terribly afraid" , "Fear - arrest" , "Detain" .)