A chap to exclude, however saintly (5)
I believe the answer is:
alban
'however saintly' is the definition.
I can't judge whether this definition defines the answer.
'a chap to exclude' is the wordplay.
'a chap' becomes 'Al' (man's name).
'to exclude' becomes 'ban' (I've seen this in other clues).
'al'+'ban'='ALBAN'
Can you help me to learn more?
(Other definitions for alban that I've seen before include "Saint born at Verulamium" , "early martyr" , "Saint who was first British Christian martyr" , "-- Berg, composer" , "Ancient Scottish kingdom" .)