Host anti-monarchy guy abandoning Religious Education (8)
I believe the answer is:
publican
'host' is the definition.
(I've seen this before)
'anti-monarchy guy abandoning religious education' is the wordplay.
'anti-monarchy guy' becomes 'republican' (republicans oppose the monarchy).
'abandoning' indicates named letters should be taken away.
'religious education' becomes 'RE' (abbreviation).
'republican' with 're' removed is 'PUBLICAN'.
(Other definitions for publican that I've seen before include "Landlord or landlady" , "Tavern keeper" , "Bar licensee" , "Mine host" , "Bar owner" .)