Support the new visionary (7)
I believe the answer is:
prophet
'visionary' is the definition.
(I know that prophet is a type of diviner)
'support the new' is the wordplay.
'support' becomes 'prop' (prop up can mean to support).
'new' indicates anagramming the letters.
'the' is an anagram of 'het'.
'prop'+'het'='PROPHET'
(Other definitions for prophet that I've seen before include "Oracle" , "reader" , "Soothsayer" , "what he says might happen" , "Forecaster (sounding like 4)" .)