Sudden belch after heart transplant in outskirts of Ashgabat (6)
I believe the answer is:
abrupt
'sudden' is the definition.
(similar in meaning)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for abrupt that I've seen before include "Sudden - blunt" , "Terse and sudden" , "Sudden, maybe rude" , "Sudden, brusque" , "Snap!" .)