A hundred over to be divided (5)
I believe the answer is:
cleft
'be divided' is the definition.
(similar in meaning)
'a hundred over to' is the wordplay.
'a hundred' becomes 'C' (Roman numeral).
'over' is a charade indicator (letters next to each other) (in a down clue, some letters go over others).
'to' becomes 'left' (I can't explain this - if you can you should believe this answer much more).
'c'+'left'='CLEFT'
Can you help me to learn more?
(Other definitions for cleft that I've seen before include "division" , "Space" , "split along natural lines" , "Narrow gap" , "Narrow opening" .)