Dismissed start of Roman era in fury (7)
I believe the answer is:
outrage
'fury' is the definition.
(I've seen this before)
'dismissed start of roman era' is the wordplay.
'dismissed' becomes 'out' (I've seen this before**).
'start of' suggests taking the first letters.
'era' becomes 'age' (I've seen this before).
The initial letter of 'roman' is 'r'.
'out'+'r'+'age'='OUTRAGE'
'in' is the link.
(Other definitions for outrage that I've seen before include "Shocked anger" , "Very angry reaction" , "Violate" , "Barbarity" , "Gross injury" .)