Ships engine parts (6)
I believe the answer is:
liners
This might be a double definition.
'ships' is the first definition.
(liner is a kind of ship)
'engine parts' is the second definition.
The answer and definition can be both acts as well as being plural nouns.
Maybe there's an association between them I don't understand?
Can you help me to learn more?
(Other definitions for liners that I've seen before include "Large commercial ships" , "These go inside" , "cruise ships" , "craft?" , "Large ocean-going ships" .)