Get some paper on account (7)
I believe the answer is:
acquire
'get' is the definition.
(I know that get can be written as acquire)
'some paper on account' is the wordplay.
'some paper' becomes 'quire' (paper measurement).
'on' says to put letters next to each other.
'account' becomes 'ac' (abbreviation for account).
'quire' after 'ac' is 'ACQUIRE'.
(Other definitions for acquire that I've seen before include "Procure" , "Buy" , "Come into possession of" , "Get" , "Bag" .)