Determination to repeat what you wish to do (7)
I believe the answer is:
resolve
'determination' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for resolve that I've seen before include "Settle, decide" , "split up" , "Decide; firm determination" , "find an answer" , "Settle; determination" .)