Ton added to gold in room a shock (6)
I believe the answer is:
trauma
'shock' is the definition.
(I've seen this before)
'ton added to gold in room a' is the wordplay.
'ton' becomes 't' (abbreviation).
'added to' is a charade indicator (letters next to each other).
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'in' means one lot of letters goes inside another.
'room' becomes 'rm' (abbreviation for room).
'au' inserted inside 'rm' is 'raum'.
't'+'raum'+'a'='TRAUMA'
(Other definitions for trauma that I've seen before include "Shock with long-lasting effects" , "Emotional upset" , "Nervous shock" , "Emotional shock, long-lasting" , "Bodily or mental shock" .)