Bond in trouble after heading to Beijing (4)
I believe the answer is:
bail
'bond' is the definition.
(I know that bond can be written as bail)
'trouble after heading to beijing' is the wordplay.
'trouble' becomes 'ail' (synonyms).
'after' is a charade indicator (letters next to each other).
'heading to' says to take the initial letters (the head of the word).
The first letter of 'beijing' is 'b'.
'ail' after 'b' is 'BAIL'.
'in' acts as a link.
(Other definitions for bail that I've seen before include "Cross piece on wicket" , "Crosspiece on a 14 across" , "In cricket, wooden cross-piece placed on stumps" , "Piece of sporting apparatus" , "Conditional release" .)