Eccentric theologian entertained by old boy meeting everyone (7)
I believe the answer is:
oddball
'eccentric' is the definition.
(an oddball is an eccentric person)
'theologian entertained by old boy meeting everyone' is the wordplay.
'theologian' becomes 'DD' (Doctor of Divinity degree).
'entertained by' is an insertion indicator (inserted letters are hosted or entertained).
'old boy' becomes 'OB' (abbreviation for a private school 'old boy').
'meeting' is a charade indicator (letters next to each other).
'everyone' becomes 'all' (all people).
'dd' placed within 'ob' is 'oddb'.
'oddb'+'all'='ODDBALL'
(Other definitions for oddball that I've seen before include "Eccentric 32" , "Bold lad (anag)" , "Strange, bizarre" , "Nonconformist - peculiar" , "eccentric type" .)