The stuff to make ship's officer bad liar (8)
I believe the answer is:
material
'the stuff' is the definition.
('material' can be a synonym of 'stuff')
'ship's officer bad liar' is the wordplay.
'ship's officer' becomes 'mate' (mate is a kind of ship's officer).
'bad' indicates anagramming the letters.
'liar' is an anagram of 'rial'.
'mate'+'rial'='MATERIAL'
'to make' is the link.
(Other definitions for material that I've seen before include "Fabric, stuff" , "I am alert to find cloth or information" , "I alert ma (anag.)" , "Substantial -- textile" , "Stuff - relevant" .)