Keen on repeating second half, considering everything (2,4)
I believe the answer is:
in toto
'considering everything' is the definition.
(Latin phrase)
'keen on repeating second half' is the wordplay.
I cannot really understand how this works, but
'keen' could be 'into' and 'into' is found within the answer.
'on' could be 'to' and 'to' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for in toto that I've seen before include "Completely - entirely (Latin)" , "All told" , "Tranquillity" , "Wholly" , "In entirety" .)