The opposite of pessimal (7)
I believe the answer is:
optimal
(Other definitions for optimal that I've seen before include "Am pilot being at best" , "Best possible" , "Most desirable" , "as good as can be" , "Ideal" .)
I believe the answer is:
optimal
(Other definitions for optimal that I've seen before include "Am pilot being at best" , "Best possible" , "Most desirable" , "as good as can be" , "Ideal" .)