Sad soldier in farm vehicle turned up (6)
I believe the answer is:
tragic
'sad' is the definition.
(I've seen this before)
'soldier in farm vehicle turned up' is the wordplay.
'soldier' becomes 'gi' (government issue or general issue).
'in' means one lot of letters goes inside another.
'farm vehicle' becomes 'cart' (I've seen this before).
'turned up' says the letters should be written backwards.
'cart' back-to-front is 'trac'.
'gi' going within 'trac' is 'TRAGIC'.
(Other definitions for tragic that I've seen before include "Resulting in great loss" , "Deeply distressing" , "Dreadful" , "Ill-fated" , "Unfortunate" .)