Reputed to give half of us help (4)
I believe the answer is:
said
'reputed' is the definition.
(I've seen this in another clue)
'give half of us help' is the wordplay.
'give' is a charade indicator (letters next to each other).
'half of' means to take half the letters.
'help' becomes 'aid' (synonyms).
'us' halved is 's'.
's' next to 'aid' is 'SAID'.
'to' acts as a link.
(Other definitions for said that I've seen before include "Aforementioned" , "Announced; Egypt. Port" , "Rumoured" , "Port ____, important site in the Suez crisis" , "Mentioned" .)