[noun] [U] - the tendency to be hopeful and to emphasize or think of the good part of a situation rather than the bad part; the belief that good things will happen in the futureThere was a note of optimism in his voice as he spoke about the company's future.Judging from your examination results, I think you have cause/grounds for cautious optimism about getting a university place.Compare pessimism.
OPTIMISM
Meaning of OPTIMISM in English
Cambridge English vocab. Кембриджский английский словарь. 2012