Pauses at "Is back among these convinced" (9)
I believe the answer is:
hesitates
'pauses' is the definition.
('hesitate' can be a synonym of 'pause')
'at is back among these convinced' is the wordplay.
'back' is a reversal indicator.
'among' indicates putting letters inside (inserted letters are placed among others).
'these convinced' becomes 'hetes' (I am not sure about this - if you are sure you should believe this answer much more).
'at'+'is'='atis'
'atis' back-to-front is 'sita'.
'sita' placed inside 'hetes' is 'HESITATES'.
Can you help me to learn more?
(Other definitions for hesitates that I've seen before include "rather dubious" , "thinks twice" , "Is somewhat lost for words" , "dithers" , "Has misgivings" .)