Large rite performed by friend verbatim (9)
I believe the answer is:
literally
'verbatim' is the definition.
(I've seen this before)
'large rite performed by friend' is the wordplay.
'large' becomes 'L' (eg in clothes sizes).
'performed' indicates an anagram.
'by' is a charade indicator (letters next to each other).
'friend' becomes 'ally' (an ally is a friend or supporter).
'rite' with letters rearranged gives 'iter'.
'l'+'iter'+'ally'='LITERALLY'
(Other definitions for literally that I've seen before include "According to the letter, exactly" , "precisely as written" , "Verbatim" , "Without exaggeration" , "Exactly as stated" .)