Steal train to make a bit of cash abroad (6)
I believe the answer is:
nickel
'a bit of cash abroad' is the definition.
(five cent coin in the US)
'steal train' is the wordplay.
'steal' becomes 'nick' (nick can informally mean to steal).
'train' becomes 'El' (El train, short for elevated railway).
'nick'+'el'='NICKEL'
'to make' is the link.
(Other definitions for nickel that I've seen before include "American 5-cent piece" , "very little money" , "Sliver of wood/glass" , "Silvery-white metal" , "Atomic number 28" .)