Cut down on one entrance at back of university (8)
I believe the answer is:
mitigate
'cut down' is the definition.
Although both the answer and definition are verbs in their base form, I don't understand how they can define each other.
'one entrance at back of university' is the wordplay.
'one' becomes 'i' (Roman numeral).
'entrance' becomes 'gate' (type of entrance).
'at back of' says to put letters next to each other.
'university' becomes 'MIT' (Massachusetts Institute of Technology).
'i'+'gate'='igate'
'igate' put after 'mit' is 'MITIGATE'.
'on' is the link.
Can you help me to learn more?
(Other definitions for mitigate that I've seen before include "Make less harsh" , "Lessen the seriousness of" , "Lessen the gravity of" , "Make less severe" , "Make less intense or serious, say offence" .)