It helps keep a tight ship tight (5)
I believe the answer is:
rivet
(Other definitions for rivet that I've seen before include "fix" , "Arrest" , "join securely" , "Metal pin; engross" , "Heavy fastening pin with head and hammered end" .)
I believe the answer is:
rivet
(Other definitions for rivet that I've seen before include "fix" , "Arrest" , "join securely" , "Metal pin; engross" , "Heavy fastening pin with head and hammered end" .)