Locomotive (6)
'locomotive' is the definition.
(I know that locomotive can be written as engine)
This is the entire clue.
(Other definitions for engine that I've seen before include "Motive machine" , "Machine with moving parts" , "turn of mind once" , "Power unit" , "search, maybe" .)
'locomotive' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for train that I've seen before include "Suite; give practice (in)" , "Try to get fit" , "one thing after another" , "held up in union action?" , "Teach, retinue" .)
'locomotive' is the definition.
(iron horse is a kind of locomotive)
This is all the clue.
(Other definitions for iron horse that I've seen before include "worn-out engine" , "An invention of the steam age" , "Old name for locomotive" , "one's gone off the rails" , "Train leader" .)