Prefect turned out to be ideal (7)
I believe the answer is:
perfect
'be ideal' is the definition.
(similar in meaning)
'prefect turned out' is the wordplay.
'turned out' indicates an anagram (turn out can mean to organise).
'prefect' with letters rearranged gives 'PERFECT'.
'to' acts as a link.
(Other definitions for perfect that I've seen before include "Past tense; ideal" , "Ideal, without flaw" , "Getting by scheming" , "Exemplary" , "Make right" .)