Wagon overturned on eastern trail (5)
I believe the answer is:
trace
'trail' is the definition.
(tracing is a kind of trailing)
'wagon overturned on eastern' is the wordplay.
'wagon' becomes 'cart' (cart is a kind of wagon).
'overturned' is a reversal indicator.
'on' says to put letters next to each other.
'eastern' becomes 'e'.
'cart' reversed gives 'trac'.
'trac'+'e'='TRACE'
(Other definitions for trace that I've seen before include "Element" , "Find - tiny portion" , "description of some elements?" , "Find by investigation" , "Copy; describe; draw" .)