Something irrational in male saint that's rejected top deity (8)
I believe the answer is:
olympian
'deity' is the definition.
(Olympian is an example)
'something irrational in male' is the wordplay.
'something' becomes 'oly' (I can't explain this - if you can you should believe this answer much more).
'irrational' becomes 'pi' (an irrational number).
'in' means one lot of letters goes inside another.
'male' becomes 'man' (man is a kind of male).
'pi' going inside 'man' is 'mpian'.
'oly'+'mpian'='OLYMPIAN'
'saint that's rejected top' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for olympian that I've seen before include "For example, Zeus's" , "Like Zeus and his kind" , "Contestant in revival of ancient games" , "Top athlete" , "Competitor in games held every four years" .)