Ideal tense (7)
I believe the answer is:
perfect
This clue is a double definition.
'ideal' is the first definition.
(similar in meaning)
'tense' is the second definition.
(I know that perfect is a type of tense)
(Other definitions for perfect that I've seen before include "Without blemish" , "Without fault or defect" , "Flawless - finish" , "Faultless" , "Make right" .)