Train passes by the European (6)
I believe the answer is:
diesel
'train' is the definition.
(I've seen this before)
'passes by the european' is the wordplay.
'passes' becomes 'dies' (passes away).
'by' means one lot of letters go next to another.
'the european' becomes 'el' ('the' in Spanish).
'dies'+'el'='DIESEL'
(Other definitions for diesel that I've seen before include "Vehicle fuel" , "Common fuel for heavy vehicles" , "Eponymous German engineer" , "Motor fuel" , "Lorry fuel" .)