Get a size of paper on account of the college (7)
I believe the answer is:
academy
'college' is the definition.
(both can mean an educational institution)
'get a size of paper on account' is the wordplay.
'get' is a charade indicator (letters next to each other).
'size of paper' becomes 'demy' (I've seen this in another clue).
'on' says to put letters next to each other.
'account' becomes 'ac' (abbreviation for account).
'a' put next to 'demy' is 'ademy'.
'ademy' put after 'ac' is 'ACADEMY'.
'of the' is the link.
(Other definitions for academy that I've seen before include "Place of specialised study or training" , "School for specialised education" , "Learned institution" , "Training school" , "institute" .)