Current arrangement is perfect (5)
I believe the answer is:
ideal
'is perfect' is the definition.
(similar in meaning)
'current arrangement' is the wordplay.
'current' becomes 'I' (symbol for electric current).
'arrangement' becomes 'deal' (arrangement between two people or groups).
'i'+'deal'='IDEAL'
(Other definitions for ideal that I've seen before include "Benchmark" , "Standard to aim for" , "Textbook" , "Just right" , "Perfect but not likely to become a reality" .)