A bishop is seen before having departed (7)
I believe the answer is:
prelate
'a bishop' is the definition.
(I've seen this before)
'before having departed' is the wordplay.
'before' becomes 'pre' (prefix meaning 'before').
'having' says to put letters next to each other.
'departed' becomes 'late' (late can mean deceased).
'pre'+'late'='PRELATE'
'is seen' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for prelate that I've seen before include "priest" , "High-ranking member of clergy, say bishop" , "Senior churchman" , "e.g. Bishop" , "Bishop perhaps" .)