Need a difficult craft (8)
I believe the answer is:
'need' is the definition.
(I've seen this before)
'a difficult craft' is the wordplay.
'a difficult' becomes 'hard' (I've seen this in another clue).
'craft' becomes 'ship' (ship is a kind of craft).
(Other definitions for hardship that I've seen before include "Privation difficult to endure" , "Difficult circumstances" , "Difficulty, vicissitude" , "Severe discomfort or deprivation" , "Adversity, misfortune" .)