Unhappy, then led astray, resulting in charge (6)
I believe the answer is:
saddle
'charge' is the definition.
(synonyms)
'unhappy then led astray' is the wordplay.
'unhappy' becomes 'sad' (associated in meaning).
'then' is a charade indicator (letters next to each other).
'astray' indicates anagramming the letters.
'led' with letters rearranged gives 'dle'.
'sad'+'dle'='SADDLE'
'resulting in' acts as a link.
(Other definitions for saddle that I've seen before include "Lumber (with); one on horse" , "land" , "Butcher's cut from the back of an animal" , "Jockey's seat" , "Burden; seat" .)