Graduate gets weapon that's left over (7)
I believe the answer is:
balance
'left over' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'graduate gets weapon' is the wordplay.
'graduate' becomes 'BA' (someone with a Bachelor of Arts degree).
'gets' means one lot of letters go next to another.
'weapon' becomes 'lance' (lance is a kind of weapon).
'ba'+'lance'='BALANCE'
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for balance that I've seen before include "Rest" , "Sign" , "Weighing apparatus" , "Surplus" , "Cab lane (anag)" .)