upbeat

名词 upbeat:

1. a contented state of being happy and healthy and prosperous
   同义词：wellbeing, well-being, welfare, eudaemonia, eudaimonia
2. an unaccented beat (especially the last beat of a measure)
   同义词：offbeat

形容词 upbeat:

1. pleasantly (even unrealistically) optimistic
   同义词：cheerful, pollyannaish