Too restricted by ceremonial sometimes (4)
I believe the answer is:
also
'too' is the definition.
('also' can be a synonym of 'too')
'restricted by ceremonial sometimes' is the wordplay.
'restricted by' indicates the answer is hidden within the clue.
'ALSO' is hidden in the letters of 'ceremonial sometimes'.
(Other definitions for also that I've seen before include "Furthermore" , "an indication of more to come" , "Old" , "As well, in addition" , "'Besides, moreover (4)'" .)