Initial repetition is only repetition after all (12)
I believe the answer is:
alliteration
'only repetition after all' is the definition.
I can't judge whether this definition defines the answer.
'initial repetition' is the wordplay.
'initial' becomes 'all' (I am not sure about this - if you are sure you should believe this answer much more).
'repetition' becomes 'iteration' (iteration is a kind of repetition).
'all'+'iteration'='ALLITERATION'
'is' is the link.
Can you help me to learn more?
(Other definitions for alliteration that I've seen before include "Poetic rhyming device using words with the same initial letter" , "Poetic ploy practised with panache!" , "Peter practised poetic ploy perfectly" , "Successive starts sounding similarly" , "Repeated first letters" .)