Again prevail upon to go round and say hello to (5)
I believe the answer is:
greet
'say hello to' is the definition.
(I've seen this before)
'again prevail upon to go round' is the wordplay.
'again' becomes 're'.
'prevail upon' becomes 'get' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'to go round' indicates putting letters inside.
're' inserted within 'get' is 'GREET'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for greet that I've seen before include "Make welcome" , "Welcome; cry (Scots)" , "Receive (someone)" , "Welcome (someone)" , "Receive - salute" .)