Raised floor on both sides back in The Boom (4)
I believe the answer is:
roar
'the boom' is the definition.
(synonyms)
'raised floor on both sides back' is the wordplay.
'raised floor' becomes 'oa' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'on' indicates putting letters inside.
'both sides' suggests removing the centre (I've seen 'both sides of' mean this (only the letters on the sides remain)).
'back' becomes 'rear' (something's rear is its back).
'rear' with its centre removed is 'rr'.
'oa' inserted inside 'rr' is 'ROAR'.
'in' is the link.
Can you help me to learn more?
(Other definitions for roar that I've seen before include "Bawl, bellow" , "cheer" , "Loud cry" , "Make a loud noise" , "Great cry" .)