Depressed as liberal enters assembly (8)
I believe the answer is:
conclave
'assembly' is the definition.
(I've seen this before)
'depressed as liberal enters' is the wordplay.
'depressed' becomes 'concave' (similar in meaning).
'as liberal' becomes 'l' (abbreviation. I am not sure about the 'as' bit.).
'enters' indicates putting letters inside.
'concave' enclosing 'l' is 'CONCLAVE'.
Can you help me to learn more?
(Other definitions for conclave that I've seen before include "Papal election meeting" , "Confidential or secret meeting" , "Secret assembly" , "Private meeting, perhaps of cardinals" , "An assembly of Catholic cardinals" .)