Union leader in public vehicle getting over a shock (6)
I believe the answer is:
trauma
'shock' is the definition.
(I've seen this before)
'union leader in public vehicle getting over a' is the wordplay.
'leader' indicates taking the first letters.
'in' is an insertion indicator.
'public vehicle' becomes 'tram' (I've seen this before).
'getting over' means one lot of letters go next to another (in a down clue, some letters go above others).
The initial letter of 'union' is 'u'.
'u' put into 'tram' is 'traum'.
'traum'+'a'='TRAUMA'
(Other definitions for trauma that I've seen before include "Lasting shock or disturbance" , "Psychological wound" , "Emotional shock, long-lasting" , "dreadful shock!" , "Extreme shock" .)