Graduate left ultimate stuff to provide stability (7)
I believe the answer is:
ballast
'stuff to provide stability' is the definition.
I can't tell whether this definition defines the answer.
'graduate left ultimate' is the wordplay.
'graduate' becomes 'BA' (someone with a Bachelor of Arts degree).
'left' becomes 'l' (common abbreviation).
'ultimate' becomes 'last' (similar in meaning).
'ba'+'l'+'last'='BALLAST'
Can you help me to learn more?
(Other definitions for ballast that I've seen before include "Material used to stabilize a ship" , "Stabilising weight (naut.)" , "Heavy material in ship for stability (7)" , "Stabilising material" , "Material for railway bed" .)