Paper encompassing Liberal's field of study (5)
I believe the answer is:
realm
'field of study' is the definition.
(I've seen this before)
'paper encompassing liberal's' is the wordplay.
'paper' becomes 'ream' (I've seen this before).
'encompassing' is an insertion indicator.
'liberal' becomes 'l' (abbreviation).
'ream' enclosing 'l' is 'REALM'.
(Other definitions for realm that I've seen before include "King's domain" , "Area of knowledge under discussion" , "Monarchy" , "monarch's responsibility" , "region" .)