Check the forepart of the ship (4)
I believe the answer is:
stem
This could be a double definition.
'check the forepart' is the first definition.
'stem' can be an answer for 'check' (both can mean to control or stop). I'm not sure about the 'the forepart' bit.
'ship' is the second definition.
(thesaurus)
'of the' acts as a link.
Can you help me to learn more?
(Other definitions for stem that I've seen before include "root" , "Dam" , "Stop; stalk; ship's timber" , "Ski turn and plant stalk" , "Thin vertical part of glass or plant" .)