General's one to hold public address (7)
I believe the answer is:
agrippa
'general's' is the definition.
(I have seen 'Old general' mean 'agrippa' so perhaps 'general' could also mean 'agrippa')
'one to hold public address' is the wordplay.
'one' becomes 'a' (a thing is one thing).
'to hold' becomes 'grip' (gripping is a kind of holding).
'public address' becomes 'pa' (this could be a standard abbreviation I've not previously seen).
'a'+'grip'+'pa'='AGRIPPA'
Can you help me to learn more?
(Other definitions for agrippa that I've seen before include "Acts reported of this king" , "10 [GENERAL]" , "Roman leader" , "one of the Herods" , "Old general" .)