Tumult formerly with a capital T (4)
I believe the answer is:
riot
'tumult' is the definition.
(I've seen this in another clue)
'with a capital t' is the wordplay.
'with' means one lot of letters go next to another.
'a capital' becomes 'rio' (I've seen this before).
'rio'+'t' is 'RIOT'.
'formerly' is the link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for riot that I've seen before include "Debauchery" , "Public disorder" , "loose living" , "The unruly may run this" , "Civil disturbance" .)