Initially dampen excitement that runs round room (4)
I believe the answer is:
dado
'that runs round room' is the definition.
I can't judge whether this definition defines the answer.
'initially dampen excitement' is the wordplay.
'initially' says to take the initial letters.
'excitement' becomes 'ado' (I've seen this before).
The first letter of 'dampen' is 'd'.
'd'+'ado'='DADO'
Can you help me to learn more?
(Other definitions for dado that I've seen before include "strip running round room" , "Low wall panel" , "stretch of wall" , "Wooden border" , "Differently finished lower part of an interior wall" .)