Only about half ripe, suddenly (6)
I believe the answer is:
openly
'suddenly' is the definition.
Both the answer and definition are adverbs. Perhaps they are linked in a way I don't understand?
'only about half ripe' is the wordplay.
'about' indicates putting letters inside.
'half' suggests halving the letters.
'ripe' with half the letters taken is 'pe'.
'only' enclosing 'pe' is 'OPENLY'.
Can you help me to learn more?
(Other definitions for openly that I've seen before include "Candidly, without concealment." , "In an overt way" , "In public" , "In frank and candid manner" , "Above board" .)