Flog some diesel locomotives (4)
I believe the answer is:
sell
'flog' is the definition.
(I know that flog can be written as sell)
'some diesel locomotives' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'SELL' is hidden in the letters of 'diesel locomotives'.
(Other definitions for sell that I've seen before include "What shops do" , "Decorative edging" , "Flog" , "Dispose of, maybe in 23" , "Exchange goods etc. for money" .)