Intellect of leader of Brexit shower? (5)
I believe the answer is:
brain
'intellect' is the definition.
(I know that brain is a type of intellect)
'leader of brexit shower?' is the wordplay.
'leader of' says to take the initial letters.
'shower?' becomes 'rain' (synonyms).
The first letter of 'brexit' is 'b'.
'b'+'rain'='BRAIN'
'of' is the link.
(Other definitions for brain that I've seen before include "Clever type" , "It's in the skull" , "Intelligence" , "Whack on the head" , "Clever person" .)